Author Topic: Journey of my 1979 T/A: Olds 403 to Turbo 5.3 LS (Rebuild of Lost Thread)  (Read 280 times)


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Hello, everyone!

I periodically get asked for links to a build thread of my project car, and currently the only documentation I have out there is on Facebook, and that isn't the easiest way to follow along with steps to a build in my opinion. I previously had a complete build thread on this car here which appears to have been lost in the database crash--so, I would like to rebuild my old thread using the data I have stored on my Facebook album.

This may take me a while to get everything re-typed and uploaded again--I'll work as quickly as I can.

Long story short: This car started life as an Olds 403 powered car, and I tried my darndest to keep it that way--but the engine that was in the car was plagued with issues as I found out a while after I owned it. The engine always burned oil like crazy--like 1 quart every 200 miles or so--and the first serious problem it gave me was spinning a rod bearing. The machine shop revealed to me that the crankshaft was bent slightly. The machine shop straightened the crank as best they could and spray-welded up the bad rod journal and I put it back together. Still burned same amount of oil after new rebuild for reasons that still boggle my mind. Always had problems with the car running too hot, replaced radiator, still ran hot from time to time, ended up spinning another rod bearing a little later on. That time when I pulled it apart I found a blown head gasket, and the deck of the block cracked on that side. It was at that point I decided to scrap that engine and build the turbocharged 5.3, with the goal of having as clean of a swap as possible with all the factory features such as A/C, cruise, windshield washer, shaker scoop, etc., still functioning just like stock.

What I started with:

What I ended up with:

How it drives:

« Last Edit: June 09, 2021, 12:20:23 PM by 79TA_Bassist »


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I'll start at the beginning, back when I first bought the car.

Back in 2009, I drove a 1989 Trans Am, and I spent all summer fixing it up. It had a new engine, transmission, paint, and interior. It looked brand new! Sadly, the total restoration only lasted about 3 months, as a careless driver ran a stop sign and slammed into the side of the car, totaling it out. Neither of us were hurt physically, thank goodness--but mentally, well, that was a different story. All my hard work just completely down the drain. I was so upset I couldn't even stand the thought of restarting work on that car.

That's when I found this '79 for sale near me! It was priced right, so I snatched it up. Here are some photos of it from when I very first brought it home:

My first order of business was to polish the paint and see what kind of shape it was REALLY in--MAN, was I PLEASED!!  :-D

Once that was done, it was time for decals--then after the decals had sat for quite a long time--wax! Another monumental improvement!!

I did a bit of touch-up on the interior, too--including repainting the black on the steering wheel spokes:

I drove it around like this for a while--maybe 6 months or a year, and then came time for me to rebuild the engine the first time. While I had it apart, I cleaned and painted it, and put a 214/224, .472/.496 cam in the Oldsmobile 403 engine along with some ported and polished 7a heads off a 1972 Olds 350--cleaned up the engine compartment real nice!

I enjoyed the car like this for another couple of years before the engine went south again... It was always a pleasure to drive--except for burning a quart of oil every 200 miles, running hot occasionally, the constant valve cover leaks, the constant carburetor problems (boiling fuel and flooding, mostly) and little random fluid leaks here and there.
« Last Edit: June 10, 2021, 08:37:43 AM by 79TA_Bassist »


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I got married back in 2014, and wanted to use this car as the "getaway" car after the wedding--so that meant it was in need of some serious interior work, as the original seat covers were quite rotten. I procured some marine-grade vinyl from Hancock Fabrics, and some baby bumper padding material from Wal-Mart, and went to work hand-sewing some seat skins, door panels, headliner, and visor covers. I VERY GENTLY removed and disassembled the factory seat covers (and when I was finished, I tucked them away in storage in an airtight container) and used them as a pattern for making the pleats, sizing, etc. I didn't have a sewing machine, so doing this by hand took quite a long time--something like 6 months if I recall correctly. I settled on two-tone black and red because I've always liked that look. The red I went with was a bit brighter than the factory burgundy and more closely matches the exterior of the car which I like also, so I dyed the dash, console, door handles, etc., to match the new fabric. When all that was done, I stitched up some black carpet and ordered a new set of floor mats. I was THRILLED with how the interior turned out!!

Out with the old, rotten, dirty carpet:

One of the new, finished front seats:

Finished rear seat bottom next to an original:

Finished front and rear next to a new front and rear:

Made me up a door panel out of parts of the original panel, some new vinyl, some dye, carpet, and pegboard for the backing for the whole thing:

Painted up all the interior pieces to match the new two-tone interior:

Made a new headliner out original-style perforated vinyl, and sewed up some visor covers out of the same material:

Painted up the dash, steering wheel, and console:

Finished product:

(This one was taken at a later date--ignore the dirty floorboards!  :-D)

Now on my SECOND engine rebuild with the Olds 403 (unfortunately I do not have any documentation or pics of that one), I decided it was time to change from the 2.73 gears to a set of 3.42's to make the cam a little happier. At this same time, I installed a Performabuilt 2004R transmission and a 2400 stall lockup converter. I do have some pics of the gear swap--but unfortunately, I did not have the foresight to take pics of the 2004R swap. I used a Shiftworks kit to keep my factory shifter, and I kept my factory driveshaft and crossmember, just moved the crossmember back to the TH-400 holes in the subframe. For the TV cable, I used the angle pattern online to weld a bellcrank to my stock Quadrajet linkage and that worked great!

I ended up with what I believe was a pretty good pattern on the gear install. I used Yukon gears:

I also painted the rear end up nice before reinstalling it, going so far as to try to replicate the marks that came on it from the factory:

This configuration didn't last long, unfortunately, as the engine self-destructed a third time (this was when I found the cracked block and another spun rod bearing). I decided that the Olds 403 engine wasn't salvageable and decided to move on to something a little more reliable. My requirements were that I didn't want to lose any power, it had to be reliable, I have always liked the way that the Quadrajet feels with its huge surge of power when the secondaries open up so I didn't want to lose that feeling, must sound good, must retain most/all functioning factory equipment (especially shaker scoop) and must look stock from the outside with the hood closed when finished. I eventually settled on a turbo 5.3 due to the relatively low cost of a junkyard engine and the fact that the turbo kicking in at higher RPMs would help me keep that "surge of power" feel I loved with the quadrajet.

Here's the last pic I took of the car with the 403 engine installed:

Next post, I'll start getting to the exciting stuff!  8-)

« Last Edit: June 09, 2021, 12:51:56 PM by 79TA_Bassist »


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I scored a complete, running donor 5.3 from a junkyard complete with wiring harness and ECU for $450--it just had high-ish mileage (220,000). I figured that part didn't matter, since I was going to rebuild it anyway.

First I disassembled the engine for inspection. Pulled the heads. Other than a lot of sludge/varnish buildup and a couple of broken exhaust bolts, they didn't look awful.

Even at 220,000 miles, the engine still has quite a bit of visible cross-hatch left:

Not totally clean yet, but much better. A quick bath in cleaning solution with the valves removed and guides brushed out. Now I can start inspecting this head to determine what, if anything, needs to be refreshed.

All the valve stems spec out perfect--.3135 inches from top to bottom, just as they left the factory.

6 out of the 8 valve guides in this head show some minor wear, but are still within spec... .0025" of guide-to-stem clearance consistently across all 6.

The other two--the two center intake valves--not so good. One of these measured .0055" of guide-to-stem clearance, and the other was .0045--both over the max wear tolerance of .0037. Looks like this head will go to the machine shop to have these two guides replaced and the valve seats re-ground to match.

Got these in the mail--twin Walbro 255 lph fuel pumps.

Wasn't having much luck cleaning the gunk out of the intake ports, so I broke down and invested in this Dremel flex shaft tool. I'd highly recommend this tool to anyone with a Dremel--gets in to some tight spots and is much easier to control.

The good news: Thanks to the flex-tool, the head came completely, spotlessly clean.

The bad news: Once the head was clean, I tried lapping an exhaust valve to check the valve head and seat integrity. This picture was taken AFTER the lapping  :(. This exhaust valve is pitted badly enough that lapping wouldn't save it, and the other 7 exhaust valves are in the same shape. So, that'd be $200 dollars for a valve job to correct the situation plus the cost of any valves that needed replacing. In light of this (valve job + resurfacing + replacing 6 guides + removal of two broken studs = $$), I'm throwing in the towel on this particular set of heads. I've ordered a remanufactured set for $350, and I'll inspect them and measure all clearances once they arrive to be sure they're of high quality.

More bad news: All 8 cylinders mic'd out flawlessly. However, while this engine was at the junkyard, someone removed the #6 fuel injector and left the hood up and rainwater collected in cylinder 6. As my luck would have it, the piston just happened to be at the top of its stroke and the rust left some pretty nasty pitting--so I'll need to send this block to the machine shop for an over-bore and new pistons. Such a shame with the bores in such good shape, but I've mic'd the factory pistons and they're all worn out and have to be replaced regardless so the cost isn't all that much more. This engine likely suffered the infamous LS piston slap when it was still in service due to the high clearances.

Next thing to come out is the cam. Unfortunately, one of the lobes appears to have left the factory with sub-optimal hardening, and exhibits spalling. This will need to be replaced for sure.

The bearings have seen better days, but still look a darned sight better than the ones I extracted from the 403.

Block totally disassembled and ready for the machine shop:
« Last Edit: June 09, 2021, 01:05:54 PM by 79TA_Bassist »


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Thanks for posting, but I can only see a handful of the first pictures.

1976 Trans Am LS1, 6 speed, C5 Brakes, LS1 rear 12" brakes, and much more...SOLD
My Build:

New project: 1968 Camaro LS6, T56, Speedtech, Hotchkis, DSE, Z51 13.4" front brakes, LS1 rear disks, etc.


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Thanks for posting, but I can only see a handful of the first pictures.

Strange, thanks for letting me know.

I'll see if I can figure out what's wrong.

EDIT: Ok, I THINK I got it!! Thank you SO much for letting me know before I got them all uploaded and had to redo everything yet again!! It was some kind of oddity with Google's photo hosting, I could see them all but it was because I was logged in to my Google account. I have no idea why some were visible and others were not as they're all in the same public album but I went through and redid each individual photo and they are visible for me now in an incognito tab. Thanks again!
« Last Edit: June 09, 2021, 01:08:04 PM by 79TA_Bassist »


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With most of the work I can do done on the engine for now, I've turned my attention back to the fuel tank. Since I'm going from carb to EFI, the new in-tank fuel pump needs a sump and baffle to prevent it from starving under hard cornering and acceleration. Here I've got some 22 gauge sheet metal from Lowes and cut it into a box shape--this will serve as both a sump and baffle once it's finished.

Got the sides bent up into the box shape, now just need to tack-weld them to make them hold this basic shape once it's submersed in fuel inside the tank.

Ignore the quality of the welds, I've got about three things working against me here: I'm a beginner, I've only got a cheap Chinese "buzz box" AC stick welder, and this is very thin sheet metal. The welds are ugly, but serve the purpose. This box won't bear any load--it's only purpose is to keep the fuel pump(s) submerged in gasoline during high-speed maneuvers, so hopefully tacking the box together is sufficient.

I felt like I needed to prove that I'm not just an absolutely terrible welder after the last picture. Here's proof that I can at least lay a somewhat decent bead on reasonably thick material! I'm still learning and have a long way to go.  :D

The fuel pumps will sit in the box like so, and will be supported by a thicker run of sheet metal up the back that will run from the box to the top of the tank. This whole assembly will be lowered into the fuel tank after I cut an access hole.

Got some more parts in the mail--this will be my new fuel line out from the tank to feed the engine. To make sure I have an adequate fuel supply, I'll be using -8AN (about 1/2 inch) from the tank to the engine. I included an aux plug in the photo for a sense of scale; it's actually quite large for a fuel line.

I managed to weld a T-shaped support brace together and to the plate that will cover the hole in the fuel tank. This brace will bear the weight of the dual pumps so the hose assembly won't be strained.

First mock-up: Attached the Y junction and plumbing fittings to the pumps, and attached the pumps to the back brace. Still need to add vent and return lines and electrical connections, and the whole assembly will drop down in the tank.

Finished! I'm quite proud of it--not many things I try to build on my own turn out quite this nice. The two screws sticking up are ran through rubber grommets and will serve as a way to get power to the pumps, one stud feeds one pump and the other feeds the other. I used rubber o-rings under the AN bulkhead fittings to prevent fuel leaks, and the return line will dump fuel directly back in to the sump to help minimize the chances of fuel starvation. The only thing left to do is to make a cork gasket to go between the plate and the tank, bolt everything together, and paint it!

I decided to test the assembly--it worked great!  :D

Shiny new fuel pressure regulator also arrived complete with gauge. I'll most likely mount this to the firewall and connect the two fuel rails to the 90 degree elbows in this pic. This is a return regulator (return fitting hidden under the gauge in this pic) so there will also be a line running from here back to the fuel tank. The small hose connection on the side will connect to the turbocharger housing for boost reference.

Engine is still at the machine shop, so I'm taking the opportunity to finish up the fuel tank. I've got the EFI pickup complete, so here I'm test fitting the tank under the car to see if anything will interfere. As fully expected, the AN fittings are just slightly too tall and hit the floor of the trunk, preventing the fuel tank from seating. I'll need to do a tad bit of cutting and welding to fix this--not a huge deal.

You can see the fuel filler neck is resting on the bottom of its opening even though the jack is holding the tank as far up as it'll go showing that the fittings are hitting the trunk floor.

The machine shop is seriously dragging their feet with my engine, but on the bright side that gives me time to continue sorting out my fuel system. Got the access hole cut in the trunk floor. this allows the tank to clear despite using the somewhat tall AN fittings, and also gives a nice way to get at the fuel pump(s) in the future should they ever go out. I'll make a bolt-on access cover for this hole out of sheet metal.

With all the fabrication work done on the fuel tank, it's time to clean it and prep it for paint. This is a shot of the inside of the tank--it's held up pretty well despite nearly 40 years of abuse!

Finally got the tank all clean and painted up! I mixed my own custom shade of steel out of aluminum and gloss black paint. Looks pretty close to the correct bare-metal color even if I do say so myself, and even if there ARE a few flaws in the paint (cheap paint--I won't lie, not one of the better paint jobs I've ever done, but not bad). The light makes it look darker with all the brown reflecting off of it--in person, it's really bright and glossy.

A shot of the bottom of the tank. Paint came out as good as possible considering how beat up the tank is from years of road debris and being lifted by a jack.

Close-up shot showing how nice and glossy most of the paint came out.

Coated the home-made pickup with my own recipe for a faux gold irritated look. It's a combination of gold, chrome, steel, fluorescent green and red. Intended to mimic irritated gold plating.

It'll look something like this once it's all together, minus the screws, plumbing, and electrical connections. I'll be testing the fuel pumps to make sure they hold pressure this weekend and get started prepping the car for the fuel tank to go back in.

When it rains, it pours. Crawled under the car and started wire-brushing the undercarriage so I could apply undercoating to reinstall the tank, and found this. All the bushings on the leaf springs are toast--just tapping them with a wire brush causes them to disintegrate. What stinks is these have to be replace while the gas tank is out due to that top bolt being impossible to reach with it in. Well, I'll add that to the list.

After an epic struggle, I won. I finally got the leaf spring off the car. Due to these never having been removed in 38 years, they were rusted pretty good. You can see on the threads of the one on the left where I had to cut the nut off one with my grinder. Well, I suppose these have to be replaced, too since they're the only thing holding the rear end of the car on. On down the rabbit hole we go.

Ordered bushings, bushings arrived, pressed old bushings out. Good. Laid leaf spring assembly on the bench, and found this--the bottom leaf spring is broken directly in half. Not good. That'd be why my car always looked like it sagged slightly to one side on the rear. I can't catch a break. Well--two new leaf springs ordered. On the bright side, NOTHING on this car won't be new by the time I'm done.  :-P

I've still got plenty to do even though I can't put the tank back in until the springs arrive and the machine shop is STILL sitting on my engine. I'm taking the time to line the trunk floor in sound-deadening mat. I use the stuff at Lowe's for this because it's much cheaper than the usual product they market for this purpose in magazines. I use "Peel 'n' Seal" roofing mat. It would seem to me to do exactly the same thing, I used it in my interior a couple of years back when I did the upholstery and have been very satisfied. For only $15 per roll, it's hard to go wrong.

Surprise! ...again. I'm really growing to hate surprises. Found a few small holes rusted through the trunk floor. Easy enough to fix with a fiberglass patch, but just goes to show you never know what you're driving around with.

Got a nice coat of undercoating applied. This will help shield the bottom of the car from rust and make the ride a tiny bit quieter. Mostly, it just looks better than the 37 years of rust and overspray splotches that were there before.

Another shot of the undercoating.

Made some new anti-squeak pads out of a few layers of roofing felt glued together, came out looking quite nice.

Final assembly on the tank is complete. Got the wiring harness made using a soldering iron and weatherpack connector. Unlike the factory configuration where you'd have to reach the top of the tank and unplug the fuel gauge and ground wires one at a time, my design allows you to just disconnect the weatherpack connector and drop everything in one go. Once my replacement leaf springs arrive, this tank is FINALLY ready to go back on the car.


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Reman heads arrived. They look good... unfortunately they're painted with a cheesy spray-paint inside and out. I'll need to wire-brush all that off and apply some better paint to the outside only before I install these. I'll take these heads apart and inspect them to make sure everything is in spec as advertised.

Despite the cheap paint, everything else on the heads looks great! All the valves lapped out perfectly just like the one in this picture (compare this to the horribly pitted one in my other picture, and you can get a feel for how worn the old valves were). All the guides are in-spec, some are a tad looser than others but that's to be expected with a reman unit. The heads' surfaces are flat, and the guide seals are tight. I took the opportunity while I had the valves out for inspection to apply a fresh coat of some high-quality assembly lube.

Finally--the machine shop let me have my engine back. They quite literally kept it for 40 days and 40 nights. Looks much cleaner now, except I asked them not to paint it because I was going with a custom color but they did it anyway. Oh well, what's a little more work stripping the paint back off, I suppose.

The block cleaned up very well bored .020 over. I verified the tops, centers, and bottoms of all 8 cylinders on the x and y axis.

All cylinders measure dead-on at 3.800 at all points. That's correct since the factory bore was 3.780.

Replaced all the pistons with stock replacements, since this is known to be a very tough engine straight from the factory. Measured all the piston skirts to get the piston-wall clearance, and came up with .002-.0025. That's within factory specs and MUCH better than the .004-.006 I measured before sending everything to the machine shop!

Verified all the big-ends of the rods are round, since the machine shop did a slight hone on them. You're really not supposed to resize this type of rod, so I was a bit nervous that they honed it at all. They all check out OK--not perfect, but OK. They're all round and measure out to between 2.225 and 2.2255. The upper limit for these is 2.225--but 5 tenths isn't a huge deal. It'll be okay because I also measured the rod journals on the crank, and it looks like there were a couple that were .0005 larger than the others. That appears to be why the machine shop honed some of these rods .0005 larger because they seem to correspond with the larger journals.

Crank got turned down .010 to get rid of the minor scoring and it cleaned up great. All the rod journals mic'd out to either 2.089 or 2.0895. The rods and journals appear to deviate by matching amounts, so the slight difference of 5 tenths is OK. The rod bearings are .067, which comes up to .002 rod bearing clearance--right in line with the factory specs. Mains were also turned down .010 and all measure to 2.548 along the x and y axis.

FINALLY, after COUNTLESS hours of scrubbing, bathing, and brushing, the block is spotless. Finally powered through all the mess left by the machine shop and got back down to the bare cast iron and clean sealing surfaces. This block is now prepped for paint, minus masking.

Fresh outta' painting. The light makes it look orange, but it's actually a very deep red (Viper Red). Engine will be ready for final assembly once the paint cures.

Actually did this before I painted to make sure everything was OK with the machine work, but just now getting around to posting. Double-checked all the bearing clearances--rod and main--with plastigauge. The Plastigauge agrees with my micrometers--around .002 clearance all around. Should be good to go.

Mixed up some epoxy and used a razor blade to fill in all the minor pits, scratches, and imperfections on the gasket surfaces. I did them all, but one water pump port is pictured here. I'm not worried about the epoxy failing because it'll be sandwiched between the block and a gasket. All the surfaces are now completely smooth to the touch and should seal much better.

At last, time to reinstall the crankshaft. Getting all the mains torqued down. This is my first time using a torque-angle gauge. You first torque the bolts to a specified value (15 ft-lb, in this case), then use this neat tool to tighten the bolt further a specified number of degrees. This bolt was tightened 80 degrees beyond 15 ft-lb.

Crank is all in and spins great! Turns easily, but not TOO easily--just perfect. With the 6-bolt mains of the LS, it should handle WAY more punishment than I can ever throw at it!

CC'ing each of the pistons as part of the process of calculating my exact compression ratio because knowing the compression is going to be critical for what I have planned. I've cut up a piece of plexiglass here and drilled a small 1/4 inch hole in it. Then I smeared some Vaseline around the piston crown to seal the plexiglass and attached it to the piston. Using a graduated dropper, I injected rubbing alcohol until all the air was gone from under the plate. This piston measured out perfect at 8 cc's.

Checking the end gaps on the new rings. This one checks out at .019. I want them a hair wider than that so I'll be filing these a bit to open them up wider before installing the pistons.

Finally got all the pistons in! Checking the deck height here with a dial indicator to help in calculating my compression ratio. After CC'ing the heads and pistons and taking measurements here and of the head gasket, I've come up with 9.43:1 compression which is perfect for what I want.

Installed new LS6 valve springs. This should help provide a higher degree of reliability.

These LS motors are cool. Every one of them comes with a factory windage tray--even this lowly 5.3. I've re-used the truck one in the picture above, but since I'm using an F-body oil pan I've had to cut a section off the front and open up an area around one bolt hole so the pickup tube would bolt down. You can see the section I cut off in the photo. It cleaned up nicely--for reference, the portion I cut off wasn't cleaned at all (obviously) vs the nice, shiny metal to the right. That took a lot of elbow grease.

Engine is ASSEMBLED! I had to ditch the original truck oil pan because it would have hung too low. I replaced it with an F-body pan.


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I decided that with the added power on a T-top car, subframe connectors would be a good idea. As a first step, I installed solid body bushings (right) to replace the worn-out rubber ones (left):

I'll say again--you never know what you're going to find when working on a car. This was one of the... uh... "body bushings" a previous owner has installed (is installed the right word here?) during the car's life. That's a bolt with a hollowed-out piece of allthread followed by a washer, followed by an oversized castle nut, followed by... some kind of metal-like substance. They used the bottom bushing for the top and used no bushing at all on the bottom. Plus, this was only finger-tight! Scary to learn what I've been riding with.

First subframe connector is in. You may notice that there are 4 bolt holes instead of 2... about that--I *may* have misunderstood the instructions for that first hole, then the second hole I got halfway through and realized I was drilling in a bad spot. The last two went well. When life gives you lemons, you make lemonade. Since this is the side that the fuel lines will be attached to, I took advantage of the first bolt hole and added even more structural rigidity with a leftover leaf-spring bolt that I had. That frame is going NOWHERE. The second missed hole will make an excellent practice piece for me when my mig welding supplies get here.

With the driver subframe connector in, I was able to run the fuel lines. I don't have them completely finished/terminated yet, but they're at least ran and clamped. They run side by side over the wheel well, up the subframe connector, up the front subframe, then finally exit up and at an angle beside the transmission tunnel on the firewall.

Finally--slow going, but I finally have a MIG welding setup. Stupid gas cylinder I exchanged for leaks, so I'm going to have to re-exchange it before I can MIG weld anything. Also had to install a sub-panel and outlet in the basement to power it. Spoiler alert: This Harbor Freight welder ended up being a piece of junk and I went through two of them before I finally got myself a good Hobart unit. I wouldn't recommend this particular welder to anyone who welds more than maybe one or two pieces of metal a year.  :-P

Tried my hand at a simple lap joint on two pieces of scrap metal using the cheap harbor freight flux core wire that came with the welder. Didn't come out too bad for about 15 total minutes of practice using cheap wire on relatively thick steel! Definitely not coming apart.

Then I tried my hand at welding a butt joint--welding that broken leaf spring back together (no, I'm not going to reuse it--just wanted to see if I could weld it up). This was two completely separate pieces when I started. Aside from my novice inconsistent beads, I think it came out great for a beginner using a cheap welder with even cheaper flux-core wire! I beat it mercilessly with a hammer, and it's not budging. Seems to have penetrated well. Once I get a better shielding gas tank, I think I'm ready to start fabricating to get the engine in permanently.

Time for motor mounts. I got these neat adapter plates off eBay--they attach flush to the engine with countersunk screws then accept either traditional small-block Chevy motor mounts or clamshell brackets.

Originally I was going to use some old clamshell brackets i had laying around, but changed my mind and decided to go with some 1968 Camaro style mounts (with the mount on the engine and the stands on the frame). This was for a couple of reasons: 1. The clamshell mount design with the mount on the frame practically has to have you remove your entire front suspension to change the mounts when they wear out, and: 2. These mounts are considerably smaller and will afford me less headaches trying to install A/C. Here I've had to grind a piece on the back of the mount flat to clear the mount adapter. They're advertised to clear this hump (that's what the square openings are supposed to be for), but mine definitely did not clear and would not allow the mount to be tightened down.

Before I knew the 403 block had problems, I had already ordered a Vintage Air A/C kit to help appease the wife in the hot weather. Of course, swapping engines renders the 2-groove v-belt pulley and mounting brackets useless (sigh). So, I just ordered a serpentine pulley for the Sanden 508 compressor and swapped them out.

Doing a mock-up of where the compressor will mount to check what all is going to interfere. I figure I'm definitely going to have to cut a notch out of the frame, and by the looks of this I'll need to cut out the upper right-hand portion of the passenger-side motor mount adapter to clear the A/C. This means I'll need to use the 3rd position back on the adapters to place the motor mounts. Why don't I just use a kit to relocate the A/C to the factory 403 location? Because that space in the engine bay is already reserved for the turbo!  8-)

With the motor mounts in this position, the lower-right interlocking tang interferes with the lower left-rear A/C mount boss. Here I've cut a section of that tang off for clearance. The interlocking mechanism should still have plenty of meat left to work in case of mount failure.

Another design flaw of these adapters--the bottom screw hits on the block before it tightens up. Luckily I have a surplus of grade-8 washers left over from the intake of my 403, so I just put two washers under the bolt to fix the problem. Here you can also see that I've hammered the interlocking tang in a bit to help it clear the notch I had to cut.

Frame stand temporarily attached. From here I'll bolt the engine to my transmission (which hasn't moved since I removed the 403, so this will help align things) and lower the engine down on the frame. That will let me mark where the new stands will go so I can get them attached.

Trial fit #1: A couple of the top rear cover bolts on the back of the engine are interfering with the bellhousing on the transmission, keeping it from seating completely. This engine and transmission were never designed to work together, so I expected some tweaking would be needed. Time to take the engine back out, break out the Dremel, and clearance the bellhousing.

Not my exact transmission--but one just like it (2004R). The blue markings show the pieces that needed to be clearanced to clear the engine:

Again, not my exact engine--but the blue markings show what hits the transmission on the engine side:

Trial fit #2: This one went much better. Bolts up to the transmission, plenty of exhaust clearance, plenty of oil pan clearance. Everything is level left to right, and the engine sits at a rearward slope just like stock.

In very convenient fashion, one of the holes in the frame lined right up with the bottom mount bolt holes on both sides, so that was a big help getting everything lined up like factory. I'll install and tighten these two bolts down snug before removing the engine again so the stands don't move, then drill out the remaining 4 holes and install the frame stands.

At last, the portion of the home-made A/C bracket that holds the compressor to the engine is finished minus cleanup and painting. Made this out of DOM tubing and 1/4" steel--put my new welder to use. The welds won't be winning any beauty contests, but they penetrated well and will hold. Sure beats paying $200-$400 for these!

I used a tap throughout the tubing instead of using long bolts with nuts, I think this should hold the compressor more securely.

Here's what the compressor looks like attached to the engine using these brackets. There will be one more bracket when I'm finished that bolts to the front of the compressor and holds the two idler pulleys in place.

I checked everything out to be sure the pulleys are in alignment. I don't have a fancy laser aligner, so I used a straight-edge and checked the distance at 4 points. Everything checks out at 5/32 of an inch, so the pulleys are squared up.

I also checked groove alignment with a square, The grooves line up well--hopefully this means I won't throw any belts.

Got the notch cut out of my frame to clear the A/C compressor. This took a little while. Don't worry--I'm going to weld this back up--it'll just be concave when I'm finished instead of convex.

Test fit #3 (I think? I lost count.) A/C compressor mounted to the engine, and the engine in the car. I made sure to put the compressor on AFTER the engine was in to make sure I have room to work with it--wouldn't be much fun to have to pull the engine if I have an A/C problem down the road! You can see why the frame needed to be notched. It's a tight fit.

Side view of the A/C compressor and the clearance notch in the frame. At least for now, it looks like I'll have plenty of room to hook up that bottom A/C line. I'll measure just to be sure, because the engine will have some degree of side-to-side movement when it's running.

I got the notch in the frame welded up; it turned out great even if I do say so myself! Once I spray a fresh coat of black paint on it, the notch should look seamless.

Since the Vintage Air unit moves all the heat and A/C equipment inside under the dash, I can free up lots of room under the hood. The kit comes with a block-off plate, which here I've welded into the hole and smoothed out the imperfections with body filler and a dual-action sander.

With all the filler dust cleaned off, I can start re-painting parts. Here I've given the bottom subframe rail a nice, new coat of satin black just like factory. My notch didn't end up QUITE as seamless as I'd hoped--but hey, the entire subframe is made of welding seams from the factory, so I'm not heartbroken. Still turned out nice, I think.

Same satin black on the now-smooth firewall. Should look a lot cleaner with all that A/C equipment inside, not to mention the room I'm gaining to make working on the engine easier.

Round peg in a square hole? Of course I wouldn't find this until I'd started painting, but not the end of the world. I haven't painted this section yet. The LS1 style throttle cable I got doesn't match the square hole where the Oldsmobile cable was. I'm thinking I can fix this by welding a washer over the square hole and running the cable through the washer.

Got a washer welded over the square hole, so now it's a round hole and I can attach my new gas pedal cable to it. Like most of my beginner welds, it ain't pretty--but it does completely seal off the square opening.

One other thing I had to do to make my cable work: I had to cut the end off the end of the gas pedal and weld it back on rotated 90 degrees due to the difference in how the new cable attaches vs. the old one. The hole was also to big, so I welded up the hole and re-drilled it to a smaller size. The cable fits like factory now.

Here's the reason I had to go ahead and deal with the gas pedal stuff. The fuel lines attach right behind where the gas pedal screws come out, so I needed the screws in so I could route the line out of the way. There was only one way I could bend the line and have it clear all three screws. As an extra precaution, I slid some tight-fitting vacuum caps over the pointy ends of the screws so even if the line does somehow move (unlikely), it will be between rubber bumpers instead of razor-sharp steel.

Frame motor mount stands are permanently attached and touch-up painted. Getting closer.


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Can't put the engine in until the flexplate is attached. All that's required to bolt an old-style transmission to the new-style truck engine is a crank spacer to center the torque converter (it's sitting in the center of the flexplate in the pic), and to slightly elongate the converter bolt holes. I laid the 403's flexplate over this one and shot some white spray paint straight down to give me a guide of where to elongate the holes.

Got the converter holes elongated and test fitted to converter. Fits great! Got all the rust brushed off and touched it up with paint to make it look a little less junkyard-y.

Can't put the engine in until I'm finished with the last A/C bracket. I figured out a way to cut out the circle shape by using a drill and jigsaw. Cutting it this way was GLACIALLY slow, but it worked.

After rough-cutting the shape, I took the guard off my angle grinder (dangerous and stupid, DON'T try that at home) and wedged it inside the semi-circle. The grinding stone helped to round the shape out.

Cut off some excess bulk around the corners, and used the jigsaw to notch around the bolt holes to clear the electromagnet on the compressor. Finished up the rough edges with a file.

Bracket is FINISHED! Used 2 10mmx50mm fine thread screws welded in to the bracket as studs for the two idler pulleys that will go here, and finally sanded down the grinding marks so that when I paint it, it won't look quite so rough. There's something deeply satisfying about building your own parts out of raw materials.

Bracket works great! everything lines up perfectly, and there's plenty of belt wrap around the crank and compressor.

This isn't the actual belt--it's an old worn-out belt off my Subaru, so it's 1 rib short, but it serves the purpose to show how well everything lines up.

Engine bay is all finished and ready to accept the engine.

Engine is in--this time, hopefully, for keeps. No issues installing, everything lined up and dropped right in place. Transmission bolted up without a hitch, and the torque converter and engine both turn freely.


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At a stopping point on the engine until parts arrive, so I've switched to the interior. Going to go ahead and install the evaporator from the Vintage Air kit. I started by siliconing around all the block-offs and patches I installed on the firewall to keep them from rattling. You can really tell where the 403's headers were in relation to the inside of the car by all the premature rust the heat caused.

After the silicone was applied, I insulated the firewall just like the trunk. I did the rest of the interior already before my wedding--the firewall was the only place I didn't get that go-around.

The Vintage Air unit comes with grommeted plates to run the A/C and heater hoses inside the car where the fresh air used to come in. That's one drawback of this kit--no option for vent, only recirculate. Got the inside plate installed and thoroughly sealed with silicone and weatherstrip adhesive.

This is the outside grommet plate. The hoses enter the cab where the factory blower motor used to be. From there, they run hidden through the inside of the passenger fender before exiting near the radiator and connecting to the engine.

Evaporator kit is permanently installed. Fits like it's supposed to be there. I'm looking forward to finally having cold A/C.

Got some more goodies in the mail. Now since I have the remaining parts of the accessory brackets, I can paint everything that I've not yet painted. Here I've finished spraying the alt/PS bracket, my three home-made A/C brackets, and the belt tensioner.

Ready to mount the A/C compressor permanently. One last mod was needed to make it fit better--I had to cut the bottom rear-most mounting ear off as seen in this pic. The compressor fit with it on, but it was VERY close to the frame and I was afraid if the engine flexed enough it would bump causing an annoying rattle or clunk.

A/C is all mounted up. It's hard to tell from the pic, but I ended up having to use heat to remove the heater hose fittings from the water pump and thread the two openings for NPT fittings. These will need either 90 or 45 degree elbows for the heater hoses since it's such a tight fit. The way it was before, the hoses came right out and rubbed on the control arm and that would have created a leak in short order.

One more shot accentuating just how tight a fit this engine is, even with the massive engine bay in this car. This is the other side of the engine. There's no alternator yet, but when there is one, it's going to be dang near the inner fender. Also, notice how close the power steering pulley comes to the control arm (it isn't pressed on yet--it will move even closer once that's done). There surely isn't much wiggle room.

Accessory system is mocked up minus the alternator so that I can get a visual on where to run my exhaust crossover from driver to passenger side without interfering with anything. I chose the Corvette accessory drive because it leaves a nice opening beneath the power steering pump to run a pipe through, and also leaves the most room between the radiator and engine. The only downside I've found to the Corvette setup is the stupid expensive Corvette-specific alternator required. The bolt spacing is just different enough that neither a truck nor F-body alternator will fit.


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You live, and you learn. The internet tells me I can weld normal mild steel pipe to these cast-iron truck manifolds and save a ton on custom headers because whatever kind of cast iron GM used on them welds more like steel than iron. They say all you need is to heat the manifold to 500 degrees, weld it up quickly, then cool slowly in sand. Some guys apparently weld them just straight with no pre or post heat and have no issues with cracking. Well, not me. I pre-heated, measured with infrared thermometer (500 degrees), welded, even peened the welds with an air hammer for extra good measure, re-heated, then cooled in sand. It looks BEAUTIFUL. Even fits great! Pipe exits EXACTLY where it should, and I even got to keep the O2 sensor in its correct location. BUT... there are hairline cracks in the iron. They leak like a pinhole would. I repair them, then more cracks. Just my luck. Oh well, it was good welding practice if nothing else. Looks like I'll have to go with plan B.

Meet "plan B" for the exhaust manifolds... well, most of it, anyway. Schedule 40 steel welding joints and 1/2" thick mild steel header flanges. This stuff is THICK and HEAVY DUTY, which is what I want. Not real pleased that the flanges are already warped out of the box, but for cheap eBay product I can't complain--I have a giant file to fix that. Maybe my painfully slow progress will start to speed up now that I have something to work with.

Slapped the two flanges in the press, and a little bit of strategic bending straightened them right out.

I know these are going to warp when I weld them despite them being thick 1/2" steel, so I cut them into two equal pieces to help manage the warpage. The factory cast iron manifolds also have a cut flange just like this one.

Mock-up with the plug wires. The flanges are a little too big and the plug wires touch/won't completely seat on the spark plugs. Nothing some grinding won't fix.

I used the factory manifolds to trace a line on the new flanges where I could grind away for plug wire clearance.

Before clearancing for plug wires (top) and after. Plenty of clearance now.

First piece welded together. I ground down all the welds to check for cracks/holes and fixed them as I went along. Once I got the welder set correctly and got into a rhythm, cracks and holes became a non-issue.

Used a big file to straighten what little warpage happened during welding. Came out dead-on, machine-quality smooth. It'll probably warp just a tad more when I join the two halves of the flange together, but I wanted to go ahead and get the worst of it smoothed out to help keep everything in alignment.

Driver's side = done. Well, all except for de-warping the flange... Despite my best efforts (1/2 inch thick steel, cutting in half, welding in short sections; cooling between, welding while bolted to the engine, etc.), the warping is still so severe the bolts no longer align. Out comes the torch, I suppose. Otherwise turned out very good and hopefully doesn't leak when it comes time for the pressure test. If it passes the leak test, I'm going to paint it black and wrap it.

Meanwhile, I got a sweet deal on a brand new Dorman LS6 intake off eBay that the person bought new for a project and never used. The bottom half is basically a FAST 78mm intake and they're reported to flow pretty well and even survive under moderate boost.

Because this intake has a FAST 78 bottom, I need to use the short-head FAST screws on the valley cover of the engine to make it fit. Otherwise, the bottom of the intake hits the top of the factory bolts and cracks in up to 10 spots when tightened down. You can see how much shorter the FAST screws (right) are compared to the GM screws (left).

For the steam tubes, I just ran block-offs on the rear and an LS6 tube across the front. I tried to make a 4 corner setup work but there was just no room. I don't seem to have any heat issues with this setup, as the car typically runs an average of 180 degrees cruising with the A/C on on a hot day.

Got the top of the engine cleaned, FAST valley cover bolts installed, excess paint scraped off around the intake ports, front and rear steam tube setup installed, knock sensors are in, cam sensor, and block-off for the oil pressure sending unit (I'm relocating that sensor elsewhere). The electric tape you see is only to hold the knock harness into position until I can lower the intake (so I don't pinch it) and will no longer serve a purpose once the intake is installed.

Intake is on the engine (that's the throttle cable you see strung out there on top). I went to install the intake, and realized that: A) My home-made steam tube in the rear won't work because the intake is too large and hits the tube. Now I see why GM used the block-offs. The truck's intake bolts are much too short and too fat to use on this intake. Darn it. Oh well, at least I can tell it's going to look nice once it's finally assembled! Looks like a trip to Lowes to look for longer, thinner screws.

Used some marking compound I had left over from my rear gear install to check how much contact the manifold would make with the cylinder head when tightened down. It's a bit hard to tell from the pic, but there's a ring all the way around the port. I've already air checked with RTV, and it seems to seal pretty well. I'll use some high-temp copper exhaust RTV with no gasket here to create a hopefully permanent seal.

Manifold is all patched up and coated with ultra-high temp paint, cured on an old BBQ grill. It doesn't look quite as nice as it once did when it was all ground smooth, but now it's 100% leak free so I'll take it! I'm going to wrap it anyway, so the repairs won't be visible in the end.

At this point, between all the learning and repairs, I've consumed an entire spool of welding wire. My welds are improving ever so slowly. This one isn't perfect and I would up redoing it because it was just a shade cold on the far left (the right was about perfect), but it at least looks smooth and consistent if you look past the spatter.

I was curious just how heavy my home-made manifold would be, so I weighed it against my original prototype made from the factory GM manifold. Just for kicks, I also weighed a reproduction replacement manifold designed for this same engine. My home-made manifold was heavier than stock by only 1 pound--and that makes me very happy. The cast repro-manifold tipped the scales at a whopping 16 pounds which means my schedule 40 version is actually lighter than a replacement cast manifold would be. Not too bad!

Got the manifold wrapped! I used DEI Titanium wrap. Went on very nice without needing to soak the wrap in water or anything.

I was actually planning to coat the wrap black until I learned that DEI doesn't recommend coating the Titanium wrap due to the coating that gets applied when it's manufactured (it's too slick for the coating to adhere well). I wasn't crazy about the color until I realized it matches the decals of the car--so now I'm quite okay with it. I think it makes the engine look pretty slick.

Here's the manifold hanging on the engine. I'll use studs to install it so I can clamp down on the warped flange just a bit more. It clears the motor mounts, block and steering shaft quite well.

Here's the exit location of the downpipe (under the black pulley with the Canada sticker on it). From here, a crossover pipe will attach and run to the turbo flange on the passenger side. I'm planning to keep the hot side fully divided and use two wastegates to help keep spool times in check.


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Following along. You have done a lot of extraordinary work. I cant imagine fabbing up some of the parts you have.  Not to mention sewing by hand!  Good Job!
77 T/A - I will Call this one DONE!
79 TATA 4sp-Next Project?
79 TATA - Lost to Fire!
86 Grand Prix - Sold
85 T/A - Sold
85 Fiero - Sold
82 Firebird - Sold
'38-CZ 250
'39-BSA Gold Star
'49-Triumph 350
'52-Ariel Red Hunter
'66-BSA Lightning
'01-HD RoadKing


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Following along. You have done a lot of extraordinary work. I cant imagine fabbing up some of the parts you have.  Not to mention sewing by hand!  Good Job!

Thanks for the kind words! I learned a lot doing this project--specifically how to weld! It took a long time and I couldn't imagine starting over from scratch but I enjoyed the whole experience!

Turbo came in the mail! :D This sucker is MASSIVE for a 69mm turbo, and weighs 40 lbs to boot. That's a full-size pair of scissors and wire cutters beside it, too, for scale. Now that I have these parts I can start eyeballing how I want to build my passenger side manifold.

Got the water pump installed. As is visible in the pic, I had to trim around the throttle body opening in the center and around one of the water pump bolt bosses for everything to clear. That's the price to pay when using non-GM parts. Fits great now!

Had to install a couple of 90-degree fittings for the heater hoses. Got the factory straight fittings out with channel locks and a torch, then tapped the holes for 1/2 and 3/8 NPT. Reason for this as you can see is without the 90 degree fittings the heater hose outlet and inlet point directly at the frame and suspension, and would force a sharp 90 degree bend which would likely kink the hose. This allows the hoses to hook straight up in the same direction as the A/C compressor lines.

Since the 5.3 was never designed to work with a cable-controlled transmission, I had to attach a mounting point for the cable to the throttle arm. Using the geometry shown in this picture, I was able to get one attached. The mounting point must be between 1.094" and 1.125" from the center line, and the cable must be 90 degrees perpendicular to the centerline when the throttle is opened 23 degrees. As best I can tell, my attachment point satisfies those conditions.

Quick test fit of the throttle arm to make sure it will clear the water pump. It clears the pump fine, but as you can see here the transmission cable fitting hits the elbow I installed for the steam vents when the throttle is opened. I'll need to find an alternate place to hook the steam vents because of this.

Plugged the hole I tapped with the pipe plug that came with my fuel pressure regulator. Fits nice and is flush with the top. The throttle arm can rotate freely now. Just as well, I was worried about what I would do if my water pump ever died out on the road with it being modified like it was.

Got the throttle body cleaned, assembled, and attached to the intake. I had to bend one of the coolant ports to face forward due to the truck throttle body interfering with the Corvette water pump, and also had to bend the fresh air inlet for the PCV system downward slightly to clear the throttle bracket attachment point on the intake.

I took a brief diversion from test-fitting the turbo when I figured out that I can have functioning cruise control with this engine with minimal clutter in the engine bay. This is a test rig I built using the computer that came with the engine, and a drill to turn the vehicle speed sensor. I wired up the cruise control module to all this stuff, started the drill to simulate the vehicle driving down the road, and "set" the cruise by shorting two wires together. Success! The cruise engaged and attempted to modulate the throttle to maintain speed. Best of all I can connect this setup directly to the factory 1979 cruise switch on the column for a seamless installation.

Chopped up the 5.3's throttle bracket and re-welded it back together to make this throttle bracket that will bolt to the Corvette intake and provide a place to connect the transmission cable.

Here's the home-made throttle bracket and cables all installed to the throttle body. Transmission cable runs between the gas pedal and cruise cables. When welding, the bracket looks to have moved slightly throwing the angle off a bit on the transmission cable. I'll probably just bend it back with a pair of pliers and all will be well. One thing I noticed is how much smoother the gas pedal feels with this 5.3 than it did when it was connected to the quadrajet, which would get stiff about half way down due to opening up the secondaries

Ended up making a version 2 of the throttle bracket, pictured here. The cruise cable needed to be moved back an inch or so, and the angle needed to be adjusted on the transmission cable. Since I had to move the cruise cable mount so far back, I went ahead and added another hold-down that attaches to an intake bolt for extra stability.

With the throttle bracket and associated cables all sorted out, I figured I'd start mocking up the turbo. This picture shows the ONLY location this thing will fit--and it took me about 5 days of repositioning tack-welding, and mumbling under my breath to figure that out. The radiator and e-fans are not permanently affixed yet--I just have them loosely attached to see where the turbo won't interfere. I'll post about those once I get the permanently mounted up. Same for the scoop--not attached, just there to help me gauge whether or not the hood will close.

This might be the ugliest, most complex bracket I've ever seen (yes, it's all one piece). Made from 3/8 bar stock purchased at Lowes, this bracket attaches to the cylinder head and tensioner pulley and supports the weight of the turbo so the pipes don't have to.

Here's the ugly bracket in action, it doesn't look so bad once the turbo is attached. You can see the direction the flange pipes have to point. The driver side has to go up, over, and around the tensioner pulley and the passenger side goes out toward the fender which will complicate the shape of the passenger manifold, but I have a plan for that. Just need to wait for a couple more bends to come in the mail.

I loosely installed both fenders and the hood to get a feel for hood clearance near the turbo. As seen here through the scoop hole, there's actually way more room than I expected. Not only does the hood close fine, but there's plenty of room for a turbo blanket and heat shielding on the bottom of the hood. I *think* I can even sneak a 4" exhaust pipe off the turbo. Ignore all the dust... hood has been standing in the garage for 7 months at this point. The flash on the camera actually makes it look way dustier than it actually is.

Got this in the mail! This will be my engine computer instead of the factory one. It tunes itself by using a closed-loop wideband oxygen sensor and continually learns and adjusts as you drive. It'll even control an electronic transmission if I decide to go that route in the future. Plus free boost control, infinite per-cylinder timing and fuel adjustments, something like 80 programmable inputs/outputs, the list goes on and on... really appeals to my inner computer geek. Big plus is if something breaks, the closed-loop wideband O2 will detect it and either compensate or shut down before something explodes--good luck with that on the factory ECU!


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Started working on the turbo flange. I'm keeping the hot side divided between banks, so I used 2 2" schedule 40 elbows to connect to the flange. Here's one that I smashed in the press to make it more of a square shape to match the flange, then sprayed some paint on the inside of it to mark where I should shave off material to make the transition smoother. I used this same paint-and-shave process on the other side, too.

For the other side, I didn't have much clearance between the turbo and valve cover, so I cut one side of the elbow down shorter. I cut the backside off flat to mate up with the other pipe, which has had the mating side flattened in the press

Both sides of the flange have been smoothed up with the Dremel tool to provide a flawless transition from the oval/round pipe to the rectangular ports. I'll improve on this a little more when I weld the pipe to the flange.

Got the two pipes joined up and welded to the flange. I swear I can't weld anything and stop warping to save my life. I was very careful with this part... so much so that I spent two whole days welding it up to keep from building up too much heat and it STILL warped. Big thanks to my neighbor Randy for use of his belt sander to get much of the warping out. It ain't perfectly straight, but only the bolt holes are bent slightly so with any luck and a little extreme temp RTV it should seal up just fine.

I welded this piece inside and out to hopefully minimize the chance of leaks, and to provide a smoother transition from pipe to flange. After welding, I ground the inside welds down smooth and used sanding drums and polishing wheels to make a surface that feels smooth as glass to the touch.

In preparation for building the crossover pipe, I went ahead and assembled the power steering system. I used -6 AN braided stainless with a PTFE core for the hoses. Everything hooked up very nicely.

I wanted to test the power steering pump before I got too far along since it's an eBay reman unit, so I turned the pump with a 1/2" drill while I rotated the steering shaft by hand. Once all the bubbles were bled out, I was able to turn the steering shaft with only one hand with the full weight of the engine, car, fenders, and hood on the wheels with little effort. To be honest, I was surprised that it takes such little power to turn a power steering pump. I really expected the drill to struggle--but I barely had to give it any juice at all. Most important thing is there are NO LEAKS! I'm very impressed with all these AN fittings going together and not leaking on the first try.

The good news: I got an alternator and belt, which is awesome! Measured for the belt with a flexible clothing-style measuring tape because of all my custom A/C pulleys. Turns out this engine will use a 97.5 inch belt, same as a 97/98 Mustang GT.

Here's a shot showing how nicely the belt fits. The marker on the tensioner is pointed to the "optimal" notch, meaning the belt is a perfect size and has 100% life remaining.

The bad news: When I was installing the power steering pulley, the stupid plastic piece of garbage broke off at the outer lip where the belt would ride (brand new pulley).

The worse news: When I tried to remove the broken pulley, the pulling flange (heck, that part's not even plastic--it's metal!) ALSO broke (ring in the center of the pulley pictured above. I had no choice but to go caveman on the pulley and use a hammer, grinder, Dremel, and chisel to cut through the center until I could wedge it apart and slide it off the pump.

Three days of waiting for a shipment later, I got a new METAL pulley--this one is the revised design for a 2005+ Corvette. It's the same size as the plastic one, except this one has spokes to reach a socket wrench through in case I need to remove any bolts. This one went on much nicer. Only problem is it seems to have a different backspacing than the plastic pulley. When fully seated, the pulley was a full 1-2 ribs farther outward than the other accessories. I had to rig up the pulley installer to go past the flush point of the shaft to correct the issue. You can see in this photo how much shaft is left sticking out of the center of the pulley. In a normal installation, that wouldn't be sticking out. I don't suppose it'll matter since the belt seems to align and nothing is rubbing.

Way down in the center of this pic (hard to see), you can see how close the pulley had to be pressed to the pressure line on the power steering pump. There's maybe 1 to 2 16ths of clearance between the two. Both the line and the pump are rigid, though, thankfully, so it shouldn't be an issue.

Here's an attempted shot showing the belt now tracking straight between the alternator, power steering pump, and other pulleys I couldn't capture in the shot. The power steering pulley may be a quarter mile back farther than it's supposed to be, but by golly at least the belt seems to line up now.

Passenger manifold is DONE. I decided to spare everyone the gorey details of fitting up, straightening, and leak-proofing (same as last manifold). I bolted this one to the heavy aftermarket manifold I had laying around while welding and it warped a LOT less.

Hopefully this will help explain the screwball shape of the manifold. There wasn't enough room to dump facing forward because of where the turbo and A/C are, and not enough room to dump to the center due to the upper control arm, so I dumped to the rear and made a wide-radius U-turn back toward the turbo. I had to leave room in the back for the downpipe to leave the engine bay, hence why the rear runner is straight.

Material for the downpipe came in the mail. I knew 4 inches would be a HUGE downpipe, but it really is bigger in person. I've got a pretty big hand, and I can make a fist and stick my whole hand in this pipe!

Downpipe is tacked up. It'll follow the contours of the inner fender, snake down where the factory A/C box was, then off toward the engine (to clear the rear plug wire) before turning down and exiting alongside the transmission. The passenger wastegate will be somewhere between the passenger valve cover and downpipe, hopefully leaving room for easy plug access and no torched plug wires.

The power steering pulley alignment was really eating at me, so I gave in and purchased a laser serpentine alignment tool. After just a shade more tweaking, I can rest easy knowing the pulleys are in alignment and I hopefully won't throw a belt.

Since I had the laser tool, I decided to verify the alignment of my home-made A/C bracket. It's dead-on!

Building the merge pipe this weekend. I think my awful welding is improving slowly--this picture is as-welded, no spatter has been cleaned and the welds have not been ground. Looks like the welds are coming out nice and flat with reasonable spatter and good penetration, with an even heat affected zone all the way around the welds. With all the pipe, it's starting to look a bit like an octopus.

Crossover pipe (top) and merge pipe (bottom) are completed and ready for leak checking. These took a while and are shaped odd to clear the engine, provide good spark plug access, and provide a nice shallow angle for the wastegate exits.

I was having some difficulty getting the V-bands to align properly, so I put some stainless pipe inside half of them to make them a male/female type connection. I used a Dremel cutoff wheel to notch and bend the pipe inward slightly so it didn't make for such a tight fit. This made a big difference in ease of assembly.

As I was leak checking the pipes, I found that the offshore wastegates didn't seal as well as they probably could (shocker!). So, I disassembled them both and used valve lapping compound to lap every machined surface together to make for a better fit. One other annoyance I found is that the valve stem was covered in paint that had already mostly worn away even though the valve hasn't even been operated yet. This, I'd think, would quickly lead to a sticking wastegate (VERY bad) so I wire-wheeled the paint away and replaced it with copper anti-seize lubricant. There's still some leakage now, but it's such a tiny amount that I'm sure once the engine runs and throws some soot out of the exhaust it'll seal up tight.

Got the merge pipe and crossover pipe leak-free. There were much fewer pinholes in these than the manifolds which I hope is an indicator that my welding is improving. Got both the pipes painted, cured, and wrapped

Mockup assembly of the now completed pre-turbo hot side. Thankfully this concludes the schedule 40 portion of this build. The rest of the pipe from here out will just be plain old aluminized exhaust pipe.

Another shot of the mockup assembly showing more of the crossover pipe. Everything about this build is such a tight fit--notice how close the crossover comes to both radiator hoses and how close the wastegate comes to the water pump pulley. Hopefully between the fact that the pipes are wrapped and the fact that I plan to make an extra heat shield to go around the radiator hoses, this won't cause any issues. The radiator hose itself is stainless steel (for this reason), but the ends still have to be rubber to give a place to connect to the engine. With the pre-turbo hot side complete, I'll move on to making the downpipe now.

Amazing how much faster welding goes when you don't have to grind paint off of every part inside and out beforehand. The downpipe is already mostly finished minus the o2 sensor bung, flange and bracket!

Like everything else--tight fit. Here's how much room I'll have between the inner fender and downpipe. I can either clearance the pipe with a press and/or hammer, or install polyurethane motor mounts if the rubber ones end up flexing enough to make the pipe contact and rattle.

The downpipe will exit here, alongside the transmission in the factory single exhaust location. I'm hoping to squeeze the massive 4 inch pipe all the way to the back bumper, but we'll see it I can pull that off. Should sound awesome if I can!

Here's where I currently am on my downpipe. Yes, those are explosives (fireworks) jammed in the end, and yes, that's me about to light them. That pretty much sums up how I feel about this thing right now. The entire thing is finished and leak free EXCEPT the passenger wastegate dump tube, which has a pinhole leak that I've chased for a cumulative total of 7 hours. I tried everything--cutting the pipe open, welding WAY up the pipe, cutting the pipe OFF, fixing, and re-attaching--ALL STILL LEAK. Finally I've resolved to cut it off completely, order new pipe, and start over on that piece of it, hence why the tube is absent from this photo. I sure hope the fabrication starts to go smoother soon or I may have to invest in more fireworks.  :-P

After approximately 3 weeks of suffering, grinding, cutting, and welding on my downpipe, I finally conceded that it was possessed by demons. I invited a couple of friends over to take care of that problem and now it is FINALLY leak free.

After the exorcism, all I had to do was replace the entire wastegate tube assembly with new pipe, grind away all traces of attempts #1-18, cut an access hole in the pipe to gain access to weld the joint inside AND out, and weld it up. Oh yeah, had to use a pint of holy water on it also.  :lol: VERY time consuming, but it's LEAK FREE now and ready to wrap. I'll post up the design and details once the wrap arrives in the mail and I get it covered.

At last, moving on to the cold side of the turbo.


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Started on the cold-side piping. MUCH easier! No weird angles to deal with, just stick it together and weld it up. Welds came out very nice by my standards. This pipe (if you can see past the hoses which won't be there once the car is assembled), this is the fist pipe that will go from the turbo, snake around the inner fender, and connect to the pipe that goes around the core support to the intercooler.

This pipe connects to the last one and will be hard-mounted to the core support. As you see here, the Vintage Air bracket that is supposed to hold the drier is directly in the way. No problem I hope, I think I can just cut this off and relocate the drier elsewhere.

Cut off the drier bracket, and this is how everything will go together. The center core support bracket needs just a small chunk cut out to clear the intercooler, but it isn't much. Overall not much hacking required at all considering I'm basically installing a third radiator that isn't designed to be there.

Another shot showing how the intercooler piping runs to the engine bay without me having to chop up the core support. Both sides run straight which is great because that's a few less bends to slow down the airflow, and make a 180 in the space between the outer fender and core support.

Here is the completed turbo hot side mocked up, minus the passenger manifold (which is finished, just not currently installed). It looks like an octopus with all the pipes. Pictured here are the two wastegate tubes (the smallest pipes on both sides of the downpipe), the downpipe (the big 4 inch one connected directly to the turbo), and of course the merge pipes. The picture doesn't make it look that way, but I actually was able to keep excellent spark plug access.

This is the downpipe looking down at the rear of the engine right at the firewall. Pictured where I missed wrapping a section is where the oxygen sensor will go. You can also see the bracket that I fabricated to stabilize the downpipe--it runs from the pipe to the rear of the cylinder head. This picture does show the good spark plug access unlike the last one.

Well, finally ran out of gas in my welding tank and can't get it refilled until Monday, so I went back to working under the car. Here I've finally replaced the driver leaf spring that was broken. This picture shows the spring and particularly the new bushings and hardware which look much less rotten than the ones I replaced. I figured the car would set up like a 4x4 for a while with new springs, but it actually sits perfectly like stock right off the bat.

A little random diversion, but being under the car made me think of this. My muffler came in the mail, and this picture shows the comparison between the old exhaust (left) and the new, massive 4 inch exhaust (right). Admittedly, this isn't a fair comparison because the 4 inch is a single and the 2 inch system to the left was a dual system all the way from the engine back. The 2 inch dual exhaust was actually completely adequate for the 403 that was in there, but the turbo can really use the 4 inch pipe to breath.

I've decided to move on to some wiring. Pictured here is the passenger valve cover with coil packs. The small picture in the top left isn't mine, but it shows a stock 5.3 valve cover. As you can see, I thought the stock coil brackets and wiring harness were far oversized and ugly, so I've trimmed the brackets down to what you see in this photo. I guess you could say I'm a minimalist.  :grin:

As I wire this engine, I want to tuck and hide the wires as much as possible. Since the car was originally carbureted and only had 8-10 wires total, I want to try to maintain that look as much as possible. Here, I've finished modifying the passenger coil harness (bottom). The top was what it looked like before I modified it. My version hides completely under the coil brackets and the connector runs off the passenger head down behind the engine out of sight instead of directly front and center like the factory had it. I also replaced the ugly factory electric tape stuff with nicer looking braided nylon, and soldered and heat-shrinked all connections.

Here is my modified harness installed on the valve cover. As you can tell it's nearly invisible when viewed from the top which is exactly what I was going for. Turned out great!

Got fuel rails and injectors in the mail today. I chose Holley products due to ease of configuring the Holley ECU to work with them. 48lb injectors should be correctly sized for my setup and top out around 550-600rwhp.

Injectors and fuel rails are loosely installed pending creation of the fuel lines to go from the firewall to the engine.

Cold side piping is all welded together, minus a couple of brackets. Leak checked and only found 4 tiny pinholes in this entire assembly, which is a new personal best. All that's left on these parts is some brackets on the driver's side pipes and to paint them satin black.


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I'm moving on to the electrical system so I don't completely burn myself out on welding (pun intended), and because my gauges are due to arrive this coming Wednesday. Here is where the sealed battery box will mount on the passenger side of the trunk. I haven't quite figured out how yet, but the intent is to devise a mounting system that will allow me to detach the box and move it to the center of the trunk to be able to remove the lid and get to the battery. This whole section of the trunk will be hidden by a beauty panel that I'll make. On the outside of the beauty panel will be 2 lugs to connect jumper cables directly to the battery, a master cutoff switch to disconnect the battery, and the rear fuse box. That will save me from ever having to actually remove the battery for any reason except when it needs to be replaced or cleaned.

This shot is from inside the trunk, passenger side, about where the battery box was in the previous picture looking rearward toward the tail lights. Here I've stick welded three studs--two small ones to mount a remote starter solenoid so that the gigantic battery cables spanning the length of the car will only be hot when cranking, and one large 3/8 stud to mount the ground cable to so the trunk body panels will have a ground point. I also put the large grommet that came with the battery box here to run the battery vent tube through.

These are the monster 0 gauge welding cables that will serve as my battery cables. The red one will be a dedicated starter-only wire that will run straight from the solenoid in the trunk to the starter on the engine, and the black one will run from the rear grounding lug to a bellhousing bolt on the engine to ensure the engine is very well grounded. I'll have one last ground wire that will run from the bellhousing to the interior of the car to ensure the firewall is well grounded for the gauges and instrumentation. You can see why I wanted a separate solenoid to cut the power except when starting--these large cables can carry enough current to quickly burn the car down in the event of a short. To power the rest of the car, I'll have a 200A fused 2 gauge wire running from the alternator to the passenger compartment, then finally back to the battery cutoff.

Moving on to the interior for a bit, I decided to start running wires to the engine. Compared to the stock carbureted engine, the 5.3 has a metric ton of wires. As such, there was no good place to run the wiring through to the inside of the car. The solution I came up with was to use a garbage disposer grommet, pictured here, installed in the transmission tunnel. The large opening will let me run all the wires I need from the engine to the ECU, and when I'm finished the flapped design will allow me to seal the grommet shut around the wires with silicone or RTV.

Making some spaghetti. This is a shot of the interior, looking in the driver door. As you can see, I've got a lot of work to do sorting through wires for the Holley ECU, Vintage Air HVAC system, and the remains of the stock systems in the car like power windows and locks. I've labelled every wire so I can keep track of what goes where. This isn't quite all the wiring; there will still be a few more yet.

I found a spot I think will work for mounting the Holley computer. I chose to mount it in the upper-passenger corner of the firewall right behind the glove box. This location seems to be out of the way of everything, and as an added bonus will allow me to remove the glove box to easily access the connectors on the ECU. The only downside to this location is that the two upper screws would protrude through the windshield glass, which obviously won't work. I think I'll try to tack weld these on to the firewall in reverse and make them serve as studs.

The majority of those wires visible in the previous photo are hidden among the engine here. I've been able to do a fairly good job at keeping the wiring hidden so far even if I do say so myself.  8) There's still a few more to go like the alternator and cooling sensors that I'll wire up when the gauges arrive.

Gauges came a day early!  :lol: They look great. I picked out the font and color scheme to look stock-ish and match the interior colors of the car. These gauges are several steps above the factory ones in terms of tech, and they're all full-sweep. The speedometer runs off of GPS, and will show 1/4 mile and 0-60 times. Here is what they will all look like in position.

Stumbled upon a 115k mile 4L80E transmission for a pretty good price--even though I don't want to install it yet due to introducing another potential point of failure, I decided to grab it up. The plan is to check out the insides to make sure it isn't busted (though I don't expect it should be--these units are built like Mack trucks), and install it maybe this winter when it's too cold to drive the car. Thanks to Euell D. Goodman for helping me get it home! Nothing wrong with the 2004R in there now--on the contrary, it's practically brand new and has been beefed up a bit--but going with the Holley ECU, it'll make my life much, much easier to just throw this in and be able to tune with a laptop and never have to worry about a transmission problem (probably) for the rest of my life. The only thing I'll miss really is the killer gear ratios in the 2004R, low first gear for taking off and .67 overdrive gear for low RPM cruising. This 4L80E is kind of backward from that, tall first gear and .75 overdrive for use in heavy duty towing applications. It's a fair trade in my opinion.

I'm ditching the factory glass fuse box since it's seen it's better days having been patched together with aluminum foil (no joke) by previous owners, and having corroded, burned, and melted spots. I'll be stepping up to this type of blade fuse holder with LED's that light up to show which fuse is blown. The only issues: 1) These are blocks of 6 a piece (fine, I'll just run two), and 2) These only have a single feed leg each. I'll mod these to add a second leg to each box in the coming photos to gain 4 circuits--BAT, IGN, IGN w/Cranking, and ACC.

Opened up the fuse box to study the internals. I think I have a game plan.

The plan is to use a Dremel tool to cut the power feed bus into two parts. This one will have 3 IGN circuits and 3 IGN w/Cranking circuits, so I halved it.

Since the LED indicators all share a single common wire tied to the one feed bus, I'll need to modify that part as well if I want to keep the neat LEDs functional. Here, I've used the Dremel tool to score the PCB and cut the circuit into two halves--three LEDs isolated from the other three.

Next step was to solder a jumper in to bridge the one LED that got orphaned from sawing up the PCB. This jumper connects it back with its other two matching LEDs. This was a pain--soldering VERY tiny connections.

Last step was to use sheet metal, screws, and the welder to extend the rear of the second half of the bus to accept power feed from a second circuit. Not pictured, but I've soldered another lead onto the LED board to connect to this bus when the box is reassembled. This will allow 3 LEDs to serve as indicators for the primary bus and the other 3 to indicate for the second half.

Done! Here the box is fully reassembled, one primary feed lug at the bottom for three of the circuits and the second home-made lug at the top for the other three.

Slightly more organized spaghetti. The body harness is finally finished, and each relay and loose wire has been labelled. From here, the trunk harness and dash harness will connect as separate pieces.

The two new fuse boxes: one went in the factory location (bottom) and the other fit nicely above. I've began connecting some wires and labelling which fuses do what. The dash harness will connect directly to the remaining circuits here.

This pic came out blurrier than I like, but this is the relay center for the power doors and windows which will be located under the center console, and the radio harness. I converted the factory three-wire radio hookup to a standard mid-90's GM connector so I will never have to hack up the harness to install whatever radio I want--I can just use a readily available adapter.

I don't know what this is (center of the dash, right under the speaker grille)--I think it's probably either some kind of speaker bracket or factory radio bracket, but whatever it is, it makes an awesome distribution point for power and ground. I have the main power lug and main ground lug both at this point, and the body harness is connected in accordingly. There will be one more 4 gauge wire from here to the engine bay fuse panel, then one more from there to the alternator. It's 0 gauge to the starter, 2 gauge to the passenger compartment, and 4 gauge to the alternator and each sub-panel.

Here I've made a 4 gauge wire out of welding cable to connect to the alternator, and protected it with a 20 amp ANL fuse since it has to travel all the way to the trunk. I've crimped the lug on to the cable with a hydraulic cable crimper and used pretty nylon sleeve and heat shrink tube to seal it all up and make it look presentable.

Ran some fuel lines, alternator wire, and cruise control cable. The alternator wire and cruise cable are both wrapped in black braided nylon sleeve for looks and both run into a firewall grommet to the power distribution center in the cowl, where the fresh air inlet was located from the factory. Since I'm running Vintage Air, the inlet was removed which freed up that space.

This will be the power distribution center for the engine bay inside the cowl. There will be 8 relays, a 6-fuse panel, and the cruise control module. The alternator connects directly to here to provide the maximum amount of power to the headlights and e-fans, and everything is concealed nicely out of view.

Crimped some ends on the 0 gauge starter and main ground wires and connected them here. Also installed the passenger subframe connector and began running the wire down the frame toward the trunk, until I ran out of Adel clamps. The ground goes directly on the starter bolt to provide adequate cranking power, then a separate 4 gauge battery cable runs from the back of the passenger cylinder head to the interior and grounds out the firewall and doors (for power windows and locks).

Got all the wires routed to the trunk. Here are the 0 gauge starter wire, 0 gauge main ground, 2 gauge main power feed, 5 16 gauge wires to trigger relays for fuel pumps, etc., 10 gauge power harness for the Holley EFI (because it has to run directly to the battery via the warranty), and 12 gauge power wires for the Vintage Air unit (same warranty issue, has to go all the way to the battery).

Got my awesome new radio today! It looks like the original AM radio that came in the car, but will do AUX input, Bluetooth, USB, AM, and FM, and will run subs and stereo speakers (factory sound was one single small speaker in the center of the dash and an AM only radio). There's just one problem--I ordered the incorrect bezel. I ordered the largest they had not knowing that the radio was made specifically for this car and came with the rectangular chrome adapter pictured here laying in the floor below the dash. That adapter is supposed to go over the radio and then the whole thing is intended to go in the factory bezel (long gone from this car, gone when I got it). You can see how much too small this current bezel is--there's a ton of space all around the radio face. The correct one would take up all the red flat space. So, I've ordered a reproduction bezel from eBay. It should be here next week.

This is the assembled wiring harness for the engine. This contains every single wire necessary to make the engine start, run, and drive. I've positioned the wires on the engine then ran them inside and bound them together with electrical tape to form this shape. Next, I'll test each wire to make sure they're all labelled correctly, and cover the harness in a nice, pretty black nylon loom and install it in its final resting place atop the engine.


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Started tuning the Holley computer today. I admire the simplicity of carbs--but I really dig the tuning software.

I have to tell the computer what voltages (or ohms, depending on the sensor) correspond to which values. Here, I've calibrated the computer to read data from my Speedhut transmission pressure sensor so that the computer can know the transmission pressure for logging purposes. I can also, for example, use this data to pull timing or remove boost if the transmission begins to slip to help prevent a tow bill.

I had to program each of these inputs and then assign them to pins--that was a ton of work!

These are the outputs. I ended up having to tweak this list and add a couple more to get everything to fall in line properly.

This is the type of interface the Holley ECU offers for customizing inputs and outputs. I want the computer to have control of the A/C system to mimic the factory Corvette control strategy. I was able to adapt in the Corvette A/C pressure sensor to the Vintage Air plumbing. Here, on this screen, I've set the system up to enable the A/C clutch if the air is turned on, the A/C pressure is within the allowable range, I'm not full-throttle, and the car isn't overheating. There is a similar control strategy set up for the cooling fans. I ended up having some logic reversed in this program somewhere and my fans didn't work exactly right at first (I say that to say "don't copy this setup if you have a Holley ECU!") but eventually I did figure it out and get it all working perfectly.  8-)

One of the nicest features of this computer is the "advanced table" feature that allows you to custom tailor 1D or 2D tables to do pretty much anything you can dream up. Here, I'm planning to attach an ABS sensor to a front wheel. I'll compare that speed with the vehicle speed to detect tire spin and remove timing progressively until traction is regained. I also have another table set up to remove boost in the event of traction loss. If I WANT to do a burnout for some reason, I'll install a traction control switch that will let me turn this feature off. Might save me during a wet day.

Lastly, I've set up the fuel and spark, spark is pictured here. I'll run with this timing to start as it *should* be safe until I can get the engine broken in. Everything below 0 PSI is set to the stock 5.3 timing and then I used a conservative timing table from a similar turbo engine above that, then deducted 2 degrees for safety until I can see what the engine wants. Again--this beats the HECK out of shaving HEI weights, running down the road, checking for ping, checking with a timing light and tape, trying again, etc. Just plug in the numbers and go!  :grin:

Wiring harness is all wrapped up and installed on the engine. Unfortunately, I've since had to remove parts of the nylon sleeve and replace them with regular 3/4 plastic convoluted tubing. The nylon sleeve was really difficult to work with, and due to the fact that I was having to use electrical tape to terminate it, just didn't look as good as I'd hoped.


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I've began working on parts of the exhaust. Here is a shot showing the replacement tips I'm using. These tips are made by Pypes and look just like the originals, but they're 3 inches instead of 2 so that the turbo can breath as well as possible. They're so much bigger that packing them in without having them rattle against everything is proving to be a challenge. In this photo, the new section of driver-side rear exhaust is on the top and the old is on the bottom. I'm going mandrel bent all the way from the exhaust ports on the head right out to the tailpipes.

Here is the driver rear tailpipe installed. Sits very close to the stock position. I'm taking the opportunity to correct an issue I've always had with the tailpipes dragging on the ground going into driveways, etc., as sometime in the car's past an exhaust shop mounted the previous tips too low. I've tried to tuck them up as high as they'll fit. The passenger side will have a tailpipe just like this one as the exhaust will be 4 inch to the muffler, then split into dual 3 inches after the axle.

A shot demonstrating the tight fit of the tailpipe around the fender, leaf spring, tire, and gas tank. Everything JUST fits with the big 3 inch pipe and tips. I'm a little worried that on sudden hard bumps the exhaust pipe may either rub the tire or rattle against the spring, but I'll make adjustments later if that proves to be a problem. As the car sits level, there's an acceptable amount of clearance. I still ended up having to cut apart and re-weld sections of this later on to get everything to fit just right!

Before I can do the passenger tailpipe, I have to tie up some loose ends on the gas tank. Since I'm doing away with the charcoal canister under the hood and all the associated tubing, I'll need a way to vent the tank without making the garage smell like gas fumes. This is my solution: I've repurposed a very large air compressor water trap by filling it with the same type of charcoal used in the factory charcoal canister to absorb the fuel vapors, and plugged up the drain with a screw sealed with RTV. I'll add a small screen filter on the end of the hose to keep dirt-dobbers from plugging up the vent and probably vent the air under the fender. Spoiler alert--this ended up not working too well. It worked for about a week, then the car just smelled like gas all the time. Additionally, where I had this placed, the axle came up and smashed it when I hit a bump. I ended up putting the charcoal in an inline fuel filter instead, and installing a one-way pressure valve that opens at something like 1 or 2 psi to vent the tank only when needed and all the fuel smell problems went away. I've still left this photo and post in as a "don't bother trying this" example.  :-P

Well, lesson learned: don't try to build an exhaust from scratch with the car still up on jacks. I finally got both rear leaf springs installed (permanently, this time) and lowered the car to the ground to find what I suspected--the tail pipe hits the spring on the slightest bump. So, I cut it apart and re-worked it. This is the passenger side which I think I got right this time. The splitter has plenty of room between the leaf spring and quarter panel, and the pipe goes up at 45 degrees to miss the tire before making a 90 degree turn as close to the gas tank and trunk floor as possible without being close enough to touch or rattle while the engine is running. This arrangement looks like it should work better.

Continuing on with the exhaust, I got this home-made 4" to dual 3" splitter almost completely finished when I ran out of welding wire (after JUST coming back from Lowes, no less). That's my luck!

Well, my welder died yesterday. This is a picture of what I had been working on until it met its demise--the exhaust from the downpipe back to the axle including the muffler.

Something in the back of my mind told me to purchase the extended warranty on the welder when I bought it, so I did--I'll get a full refund. I'm going to take it back to Harbor Freight, get a refund, and put that towards a new Hobart Handler 140. It'll be a 120v machine as opposed to this 240v one I have now, but it is advertised to weld the same range of material thickness and has MUCH better reviews, never really heard anything bad about the Handler 140. (Spoiler alert again--Harbor Freight would not let me do that (the extended warranty was exchange only) so I ended up having to get ANOTHER one of these machines, and it died also. I did end up with a Hobart Handler 190 after the second one which has been a great machine!!)

My thoughts on the Harbor Freight 170 Mig Welder for those interested:
The good: It's cheap, makes a very passable weld, and is easy to learn on. My very amateur self had NO problems picking up the welder and using it from the start. Great machine for the beginner, 1/3 the price of the next cheapest comparable name-brand welder, so not much to lose.
The bad: Out of the box, the machine would run, but wouldn't arc at all. Had to take the torch apart and found the main electrode wire was neither crimped nor soldered, but just hanging loose. Had to solder it up with a propane torch. After leaving the unit on for an extended period of time, occasionally the cooling fan will hang up and make an awful racket which requires restarting the machine to fix. There are no replacement parts to speak of available. The unit has the gas valve inside the torch handle and it is just a cheap plastic and o-ring mechanical valve that is actuated directly by the trigger (this is the part that just broke on mine, and a replacement torch costs nearly as much as the welder).

Back at it! Finished the exhaust system from the engine back to the axle. You can see in the photo I had to notch the muffler to clear the driveshaft... a 4" exhaust system is just a little tricky to fit under a car that already scrapes the ground every time you sneeze. The pipe turns up after the muffler and terminates with a V-band flange. From there, I'll build the portion that goes over the axle then splits into the two outlets that exit just behind the wheels. The flanged design allows the exhaust to come apart in sections for service without the need to cut it apart and re-weld.


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Well, I had to order a couple of more mandrel bends before I can continue on the exhaust, so I took the opportunity to button up the fuel system on the engine side and pressure test the intake manifold. This engine with all its rubber gaskets seals AWESOME compared to the metal 'turkey tray" gasket the Oldsmobile engine used. I pumped the intake up to 10 psi using the rig shown here, and it held that pressure for almost 5 full minutes (I don't have the pushrods installed yet for this very reason--I wanted all the valves to be closed for leak tests). The only sole leak I could find was where the throttle shaft exits the throttle body, and I believe that part probably leaked from the factory. It's such a miniscule leak that I'm not the least bit concerned and it doesn't even leak at all at pressures lower than about 5 psi. Since I'm using a speed density tune and omitting the mass air flow sensor, the tiny leak will not affect the performance of the engine or the idle one bit.

Got the boost solenoids rigged up. I chose to use MAC solenoids for $25 each rather than the $100 a piece for Holley's solenoids which look very much like these MAC ones. I don't mind doing a bit of manual calibration myself for the cost savings involved. One solenoid is used for venting pressure from the wastegates, and the other is used for filling. The solenoids control the pressure on the wastegate domes and are fed by a tiny air compressor mounted in the trunk. The higher the pressure, the more boost. I am going to try running without wastegate springs at all for the maximum level of boost control and see how that works out. If it flops, all I have to do is install some springs. I've added a sensor on to the air compressor side to trigger a check engine light if something goes wrong with the pressure output from the compressor as it should be a consistent 60 psi at all times.

Bouncing around in my usual fashion, I've turned my attention back to the interior for a bit. Got the steering column reassembled and mounted up. Installed new lock cylinder (keys used to fly out of the old one during hard cornering), ignition switch (the "off" position didn't work on the old one, and all other positions showed excessive resistance when testing), turn signal cancelling springs and cam (signals didn't used to cancel themselves out when turning), lock pin spring (steering wheel lock never worked), key warning buzzer contact (I didn't even know my car was SUPPOSED to buzz when the key was inserted, a previous owner removed this part completely), and repaired the wiring to the cruise button since I'll be using a cruise module with my new engine. Everything seems to work good as new!

Got a bracket welded to the firewall and the Dominator ECU installed permanently. I've begun the daunting task of connecting all the wires to the computer. There's close to 100 wires so it should be fun!  :lol:

It's ALIVE!!! Well, halfway--not running yet, but the computer is at least alive. This is the first sign of life my car has shown since July 5th of 2016. I plugged up the Holley computer, updated the firmware, and loaded the tune I made. This is the computer reporting back what it sees on the engine. Everything looks good! Air temp is way off (-40 degrees) because the sensor is currently unplugged. Progress!

Finally got the basic design of my battery box down! Instead of mounting it top-side up like it's supposed to be mounted, I'm mounting it on its side to allow me to remove the lid and service the battery if need be while the box remains permanently mounted inside the trunk. To accomplish this, I had to weld together a bracket shown here painted black (the battery box is pictured upside-down in relation to how it will be mounted). Without the bracket, (1) I had no way to attach the battery box to the floor of the trunk, and (2) the battery caused the box to sag and make it difficult to fit the lid. With this design, the weight of the battery is born by the bracket. I've attached jumper lugs and a master shutoff switch to the lid so theoretically I'll never need to physically touch the battery except to replace it or clean off corrosion. I've also fitted a series of relays to the side of the battery box. These relays will control the two fuel pumps, the starter, and the air compressor.


It seemed like a sensible idea at the time, but ended up causing my starter to run-on for about a second every time the engine started. You can actually hear this in the video of the first startup. I had to go back and run a wire all the way from the remote solenoid in the trunk to the "S" terminal on the starter after the car was finished to make this work right. Don't make the same mistake I did! I decided to leave the photo and post in anyways as another "what not to do" example.

In preparation of continuing the exhaust, I'm now working on finishing up everything that I can reach much easier without the exhaust in place, like the starter. Since I'm using a remote solenoid, I've chosen to jumper across the hot and start lugs on the solenoid. Here I've made a standoff by soldering two wire eyelets together with heavy-duty solder.

Maybe not needed with the remote solenoid, but since turbo exhaust runs so hot I decided to wrap my starter in a heat blanket just to be safe.

Starter is installed, and EVERY wire, hose, etc. surrounding the exhaust is either wrapped with heat-resistant wrap, made of braided stainless, or both. In addition to this, all the pipes will be wrapped. I DON'T want to take any chances cooking a wire or hose... when I installed the 2004R transmission to the 403 the car died totally without warning in the middle of the road in the dark during the first test run because the battery cable bracket came loose and the main battery cable welded itself to the header...  :shock: not happening again if I can help it.

Got the boost solenoids mounted permanently, and the 1/4" steel tube that runs to the trunk-mounted air compressor along with it. Since the downpipe will be in the way of this pipe after the exhaust is installed, I went ahead and got this part out of the way now. Also pictured here is the transmission thermostat which will help keep the transmission fluid near 180 degrees. The transmission lines, unlike the factory configuration, will be routed inside the passenger fender alongside the heat and A/C hoses.

Since the A/C compressor is also mounted underneath the exhaust manifold, it is time to go ahead and fit up the A/C hoses. Since the tool to crimp fittings onto A/C hoses was the same price as paying someone else to do it, I chose to buy my own tool and crimp on my own fittings. Crimps turned out pretty! I chose to cover the hose that wasn't near the exhaust in braided nylon sleeving for looks and added abrasion resistance, and everything that is near the exhaust will be wrapped in heat-resistant reflective tape.

Battery box is installed hopefully permanently. It's bolted to the floor of the trunk via a fabricated bracket and vented to the outside of the vehicle. An Optima Red Top battery slides in to that red bracket you see along the rear bottom edge, then the battery gets strapped down to the trunk floor through two holes in the bottom of the box at the front. The two loose wires are for the HVAC and engine computers--both the manufacturers insist that the power wires be hooked directly to the battery for warranty. If I had a regret here, it would be designing the box specifically for an Optima brand battery. I ended up changing this a little later on, because the first two Optima Red Tops I purchased both died in under a year with normal use! Not wanting that to happen a third time, I just put in a normal lead-acid battery and it's been going strong ever since.

Ladies and gentlemen... we have power!  :grin: At long last, the electrical center is complete and the battery is permanently installed. The two lugs mounted on the front of the battery box provide a means to jump/charge/test the battery, and the master kill switch at the top in the center gives a way to completely disconnect the battery from everything in the car except the charging terminals, since the battery will be such a pain to access. On the side of the box is the relay center, the rear fuse panel, the breaker for the subwoofer, the main chassis and engine ground point, and the starter solenoid. All this will be concealed nicely behind a fitted sheet of carpeted 1/4" plywood.

Tail-lights and spoiler corner have been re-sealed and reassembled. Before, the trunk would fill with water in the rain due to the dry-rotten seals under these parts. Any time I can put pieces of the car back together makes me happy--it's been many months since I've seen the tail lights.

Cowl electrical center. Yes, I know it looks like a rat's nest at the moment, but it's a rat's nest that represents 5 hours of roughing in wiring. Once I get all the wires ran from point A to point B, I'm going to group them together and wrap them up neatly. This is a huge chunk of the remaining wiring nearly finished. This electrical center powers all the non-engine related electronics under the hood.

...and it was here that this project went to sleep for 2.5 years. Life got in the way... bigtime. Bought a truck, had to rebuild the engine in that, bought a backhoe, had to rebuild the engine in that, rebuilt my grandpa's entire tractor from the ground up as a surprise to him, thankfully got to show it to him just months before he passed away  :(  then moved back home. Talk about hectic! The engine swap posts thus far have all been from 2016 and 2017... the next posts from here out happened in 2019 at a different location where I unfortunately no longer had a nice indoor area to work on the car. Still got it done anyway--just wasn't QUITE as convenient to work on!  :-P


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After 2.5 years of no progress, I got a little desperate and decided my new goal would be to do whatever the minimum I could do was to get the engine to start to make sure everything was okay with it. I wouldn't want to start up a new engine without being able to monitor the oil pressure and temperature at a minimum--so, I went ahead and assembled the new Speedhut gauges to the dashboard, cut off most of the end connectors, and soldered everything together, creating one single harness with one 12-pin connector and one 3-pin connector for ease of installing and removing.

The instructions for the tachometer mention that if you are going to take the tachometer signal from an engine computer, to add in a 4.7K-ohm resistor between the switched power wire for the gauges and the tachometer signal wire--so I've done just that here, and covered any exposed metal with heat-shrink tubing.

On the car end, I've roughed-in the dashboard harness, excluding the dash light wires and the keep-alive wire for the GPS speedometer, since those are not needed just to start the engine. Yes--it's an ugly bunch of wires--but when I finish this part, I'll wrap it neatly in a loom and it'll look much better.

...and viola--I can plug in the dash (albeit laying loose, and sideways) and monitor the engine's vital signs.

These Speedhut gauges are cool. They allow you to do awesome stuff like compensate for the voltage drop in the long, aging wiring back to the fuel gauge by specifying the number of ohms the gauge should read for empty and full. My sending unit is 0-90, and the tank is currently empty. The gauge is detecting 2 ohms for empty, meaning that the wiring is adding 2 ohms of resistance here--so I'll use 2 ohms for the empty reading, and I'll set the full reading to 90 to start with and adjust it accordingly once the tank is full of fuel and I can see what the gauge detects.

The box of parts I needed to finish getting the engine ready to go arrived right on time. Included here are the lower radiator hose, a temporary air filter, valve cover gaskets, a radiator cap, a valve cover bolt (one of the 8 got lost while moving), and an adapter for the upper radiator hose to allow me to connect the LS engine's steam vent tube.

I went ahead and stuck the temporary air filter on to prevent any more dust than necessary from entering the new engine. This filter is temporary because the engine will be turbocharged, and eventually there will be a charge pipe connected up to the intake here where the filter is and ideally the actual filter will be inside the shaker scoop (if it fits). I just didn't want to go starting up the engine with no filtration at all, and the turbo isn't ready to be connected just yet.

I'd like to add a disclaimer to the below based on my experience after running with these hoses for a bit:
The stainless portion of one of my hoses had a pinhole in it that required me to cut the hose off at that point (thankfully it was long enough I still had enough slack, otherwise I'd have had to buy another--and those things are EXPENSIVE!). The rubber boots on the end kept blowing off and spraying coolant everywhere once the engine was up to temp. No amount of clamps, sealant, headliner adhesive or superglue would stop that. I eventually had to replace the rubber hose ends with silicone, get improved clamps, and drop the chrome-plastic end caps entirely in order to use the hoses. Keep these things in mind if you decide to attempt to use these on a project. End disclaimer.

I chose to use flexible stainless radiator hoses because:

1. They look cool.
2. The hoses run near the hot turbo pipes, pictured here wrapped in the gold wrap, and I fear rubber hoses would just melt or blow out.
3. Try going to the parts store and asking for pre-molded rubber radiator hoses to fit a 1979 Pontiac with a 2001 Chevrolet engine in it. I can just bend these to fit whatever.

The areas of concern here will be the spots I've marked 1 and 2 in the photo, where the upper and lower hoses are close to that crossover pipe that feeds the turbo from the driver bank of the engine. That pipe may be 1,000 degrees or more at times--to mitigate that, I've wrapped the pipe in DEI Titanium exhaust wrap, and I'll also wrap the hoses in reflective tape (like the heater hoses here, in the bottom left of the photo) to keep some heat off. At least they aren't directly touching...

You may wonder, "What does it matter? It's a metal hose." Well, those two joints there where the metal hoses connect to the engine are actually rubber, and I am a bit afraid of melting them. Time will tell, I suppose, if I will need to try to find a different way to route that crossover pipe.

Area 3 in this photo shows where the LS engine's steam vent hose will ideally connect whenever I get the extra ends for my radiator hose in the mail next week.

Time to pour some fuel in and test the fuel pumps and braided stainless hoses! First fuel this car has had in it since 2016.

Fuel pump works great! Key on, computer commands the fuel pump to prime for 5 seconds. The bad news, though... something is leaking right off the bat.

Let this be a lesson to me--make 100% sure to go back and check that all the hoses and connections are tightened--even if "I'm 100% sure I tightened those up about 2 years ago"  :-P. Fuel pressure is GREAT--enough so that it sprayed fuel all over my trunk and began dissolving the adhesive backing of my sound deadening mat. Fortunately I was able to mop up the mess before any real damage occurred.

First leak fixed... but there's another big one under the car. Hmmm... MAYBE it has something to do with the fact that the return line back to the tank was just totally unhooked and hanging loose. There's another one of those "I KNOW I hooked that up about 2 years ago" things... Once connected, all the leaking under here stopped.

Luckily no leaks here at this junction, where the main line from the tank Y's off to feed the two fuel rails and where the return line connects to the regulator. I'm glad because that's a pain to get to to tighten.

No leaks at the front of the engine either, neither at the crossover hose nor the regulator. All is well here!

Last step in checking the fuel system is to adjust the regulator to match the fuel pressure I have specified in my tune, which is 60 PSI. The regulator was set to 45 PSI out of the box, which is a more common pressure. I went with 60 due to being turbo-charged and trying to squeeze the last ounce of performance out of my injectors.

You can see here the fuel pressure comes in dead-on at 60 PSI after the adjustments, and most of the other various engine sensors are hooked up and functioning also.

Two things that concern me: I've cranked on the engine with no pushrods and no spark plugs for probably a whole minute or more, and don't have one single ounce of oil pressure and nothing coming out of the turbo's oil feed line. Upon further research, this may be common to this series of engine (gear rotor oil pump, can't build pressure while cranking due to moving too slowly) and I should build pressure within 10 seconds of firing the engine (I certainly hope so) so I'm trying not to worry about that just yet...

...the other thing is I've poured in 5 gallons of fuel (21 gallon tank) and the fuel gauge is showing less than 1/8th of a tank... new gauge, new wiring, and new sending unit which I thoroughly tested before installing the tank in the car. I'm going to try not to be TOO concerned about this until I pour in another 5 gallon jug of fuel and it still doesn't read any higher.

A couple of years ago I finished wiring up computer connectors #1 and #2, so I started back on #3. Here it is, all finished and ready to be wrapped in wiring loom.

Computer connector #4 is complete and all buttoned up!

There's only two wires that go into computer connector #5 for my configuration--so this one is also complete and buttoned up.

Computer connector #6 is for the transmission. Since I'm re-using the 2004R I had installed just before the 403 engine died, the only two wires that go into this connector are for the speed sensor. Some day, when/if I ever swap in the 4l80e I have waiting, this connector will be re-pinned and filled with wires to control that transmission.

Cowl electrical center is FINISHED! This used to be the area where the heat/AC sucked in fresh air from the outside--but the Vintage Air unit does away with that feature completely, so this spot was free for me to use to hide wiring. Contained here is the engine fuse box, 8 engine/front lighting relays, the cruise module, and the connection point between the alternator and the rest of the electrical system.

Here's another view of the wiring work inside the cowl, as viewed from the driver side. The wiper arm linkage does not interfere with anything, which is great.

I cut the vacuum actuator off of the fresh air intake door that used to cover the spot on the cowl that I'm now using as an electrical center, zip-tied it shut, and converted it into a cover to hide all that wiring. Here I've labelled all the relays according to what they do in case I ever have electrical trouble.

Here's the former fresh air intake door installed over the cowl electrical center. You'd never suspect a thing!  8)

One of the nicer features of the Holley computer is this key switch--with it, you can select between 4 different tunes. Mine will be no crank (anti-theft), no boost (in case I ever can't find premium fuel), low boost, and high boost. I decided to install this inside the glove box. This is the glove box that shipped with the Vintage Air unit, as the factory glove box is too deep and will no longer fit in the car with the Vintage Air unit installed.

With all the wiring finished on the passenger interior of the car, I temporarily installed the dash to test fit the glove box. I did have to re-route 3 sections of the wiring harness (no big deal) and after I did that, everything fit together pretty nicely. Make no mistake--the glove box is a tight fit (I had to hold it in place to take this photo so it wouldn't pop out)--but, it does all fit and when the screws are installed it'll be fine.

I went on ahead and soldered together a wiring harness for the radio. When I wired the body of the car a couple of years ago, I installed a standard mid-90's GM radio connector instead of the factory 2 or 4 pin plug (or however many pins it had) so I could easily swap in any radio I want in the future. This cord here will plug in to any mid-90's GM vehicle and accept the RetroSound radio I have waiting to go in.

I removed the transmission pan and installed this sensor bung so I could add a transmission fluid temperature gauge. No more wondering if I'm going to toast the transmission--and with the fragile reputation of the 2004R behind this monster of an engine, that's a good thing.

I know it still looks messy--but there's the computer harness all finished and ready for the dashboard harness to be started on.
« Last Edit: June 10, 2021, 11:34:10 AM by 79TA_Bassist »


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I still have my moments... sometimes.

I have pulled my hair out over this STUPID cruise control for about 4 days now. I thought to myself, "Oh, before I put the dash back in, it would probably be a great time to test the cruise control to make sure it works" so I adjusted the tune on the Holley computer to enable the cruise control without the engine running, hooked a drill up to the speedometer cable, and began testing.

NOTHING. Test after test, NOTHING. Not so much as a click or a wiggle from the cruise module. I tested every pin on the connector, and every single one was seemingly working correctly.

So, I started Googling, and found that the 4,000 pulse-per-mile signal provided by the Holley computer was "possibly not correct for GM equipment" with no real other explanation. Lacking an oscilloscope to view the actual signal, I just went into the tune and slowed the pulse rate down to 500 pulses-per-mile so my multimeter would have time to read the voltage floors and ceilings of the square wave.

What I found was the Holley's speedometer output signal starts out a +5 volts at the bottom, and peaks at +12 volts. Armed with this information, I went to my truck ('99 Chevrolet, same exact cruise unit), unplugged the cruise module, ran a wire into the cab, hooked it to my multimeter, started the truck and crawled slowly forward, watching the multimeter.

The truck's computer output started at 0 volts and peaked at 12 volts. Well--that's probably the issue... the Holley starts out at 5 volts.

Not sure what to do, I went back to the Trans Am and stuck the multimeter back on the ECU speed signal wire. There I again observed pulses from 5v to 12v. Just as a wild-hair idea, I also connected a test light to this same pin at the same time as the multimeter so as to put a load on the wire. WHAT DO YOU KNOW--0v to 12v--just like the GM computer!!

So, I wired the test light in, and re-tested the cruise module. EUREKA!!! IT WORKS NOW!!!

Now I just have to measure the resistance of my test light, find a resistor having that same resistance, wire said resistor between ground and the speed signal wire, and IN THEORY everything should work perfectly.

Sheez.  :shock:

The gauges I'm using do not have turn signal indicators built in, so I'm just using some LEDs. Not fancying drilling holes in my nice original instrument panel, I made a crude bracket out of thin sheet metal that will go around the back of the temperature gauge and hold the LEDs in position behind the cutouts on the instrument panel (Yes I know my goal here was to do the "bare minimum" to start the engine but sometimes I just get on a roll  :-P).

Got the instrument panel completely finished--signals, gauges, and all--and cleaned up. Ready to install!

Ladies and gentlemen--for the first time in over three years, MY CAR HAS A DASH AGAIN. Came out looking great--HOLY COW what a tight fit with the Holley computer, massive wiring harness, and all the Vintage Air ductwork. Took some MAJOR shoe-horning to get this thing back together, but it seems to be holding fine. My years in college packing a car full of luggage were not in vain as that packing skill carried over here!  :grin:

Closer look at the dash, showing the Vintage Air controls, the RetroSound stereo, and the MP3 player I found on eBay, which fits the spot that the rear defroster use to be almost like it was made to be there. I'm tickled with how all this turned out!

I did away with the aging and temperamental factory fuse box completely and replaced it with these two new units. 12 fuses total for the interior, 6 fuses under the hood, and 6 in the trunk comprises the entire electrical system.

Exhaust is all buttoned up, and so are the radiator hoses. I solved the problem (I hope) of the exhaust pipe near the radiator hose by using heat resistant silicone hose in that spot, and I'll also wrap that section of hose with the reflective fiberglass starter blanket I have left over.

Dang it if this $100+ stainless radiator hose didn't have a pinhole in it--talk about ticked off.... fortunately, the hole was near the end so I was able to cut off about 3 inches or so of hose and get past it. It's now full of water and has been holding full for a few hours, held right at 3 gallons nearly exactly.

This picture shows just how CLOSE the wastegate is to the water pump pulley. It should work so long as nothing moves...  :shock: it may be 1/8" or so away.

A promising sign--oil on the bottom of this pushrod. This was the only pushrod I had installed in the engine when I was cranking it before and trying to build oil pressure--well, it looks like the oil pump is doing SOMETHING, anyways.

Valvetrain is back in! Some of the rocker arms collected some surface rust from sitting during our move--no big deal. That'll disappear once the oil starts flowing.

Junkyard coils painted up, and the valve covers reinstalled. I also tested each coil one by one cranking the engine to make sure they all work--and they appear to.

Not far away at all from trying to fire it up at last!!


Took the opportunity over my lunch break today to see if it'd start--started right up! Sounds awesome, too! Oil pressure came right up immediately.
Had to break the video in half, the wife thought she saw a coolant leak but turns out it was just because I don't have an overflow tank installed so false alarm.

Check out how the Holley computer learns--when I first tried to rev it, it tried to die--but after a couple more tries the computer figured out, "Hey, I need more fuel to rev" and started revving smoothly thereafter. Pretty cool!

1) I have the SAME DARNED LIFTER TICK that I got when I put the 5.3 together in my truck--I bought both sets of lifters from the same place, so no surprises there, I guess...

2) I have a mystery squeak/tick--could be that lifter, could be cam, exhaust leak, vacuum leak, injector... don't know... everything is still new and tight so maybe that'll go away.

UPDATE: I ran the engine until it warmed up, and BOTH THE TICK AND THE SQUEAK WENT COMPLETELY AWAY!!! YIPPEE--NO NOISES, NO LEAKS!!! Couldn't be happier.

3) Fuel gauge still doesn't read, so looks like I get the pleasure of dropping the tank...

4) The buzzing at the start of the video after the engine has already started is just the ignition switch slightly out of adjustment--it thinks it's off, so it's buzzing reminding me to take the key out.

Alternator and power steering both work great also! I wasn't sure about either of these since both are parts that are supposed to be on a mid-2000's Corvette.

It sounds SO good... feels great to hear it run again after 3 years of on and off work and having to look at it just sitting there. The exhaust still needs two tailpipes connected, hopefully when I do that it doesn't change the way it sounds at all.
« Last Edit: June 10, 2021, 11:35:40 AM by 79TA_Bassist »


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Today, the car moved under its own power for the first time since July 5th, 2016. Even though the project is far from complete, it feels like about 10,000 pounds have been lifted off my shoulders just from having it running and moving again.

Good to see the posi still works. No problems laying rubber, no use of the brakes even required--just stomp it and proceed to dig up the ground. The 5.3 that's in it now feels about the same as the 403 it replaced in terms of power from just puttering around the yard here, kind of hard to really tell until I can get it on the road. Just WAIT until all the turbocharger plumbing is connected, though...  :cool:

With the car running again, it's time to do something about the shaker hood scoop. I'm determined to keep my functional shaker, or die trying. An engine swap is one thing, but keeping factory options like A/C, cruise control, and a functional shaker scoop (OK--so the "functional" part of that last one isn't exactly factory) just adds a whole 'nother level of "complete" and "cool".

Here we have a pizza pan. Not just any ordinary pizza pan... it's a 17 inch, 1-inch deep, plain steel pizza pan that I scoured the earth for. Finally had to special order one off some industrial cooking site. You really have NO idea how hard it is to find cooking ware that isn't either aluminum, copper, non-stick, Teflon, etc. and THEN in an exact dimension like this...

ANYWAY, this pizza pan will become my new shaker scoop base, since I don't fancy hacking up either the factory shaker base for the 403, nor the factory shaker scoop.

First things first--although I scoured the earth for this pizza pan and it was the closest thing to "exactly the right size" I could find, it's still about 1" too narrow diameter-wise. To fix this, I've made a single cut from one side to the other like Pac-Man, so I can expand the ring around the top to fit my shaker scoop's mounting ring. Then (not pictured), I welded a piece of sheet metal all the way across to "sew it back together".

Now--I absolutely want this shaker to be functional in the way that it will feed cold air to the engine--so, next on the list is a snorkel tube. Here I've just taken a short section of 4 inch exhaust pipe, squashed one end of it in the press, then cut and trimmed it repeatedly until it fits nicely up against and underneath the pizza pan. This will serve as the point of connection for the engine's intake pipe.

The coil packs are just a bit too tall to make this work as-is, so I had to cut two notches in the pipe to allow clearance for the coil pack connectors. Later, I'll weld these back up "inverted" so that the pipe will be sealed off.

Here's a mock-up of what I'm thinking will work--just need to start tacking everything together.

I needed a way to mount the shaker base to the engine--and these Gen-III engines have very convenient studs all across the valve covers between the coil packs. I decided to use 4 of these studs and some wing nuts to make the base easy to mount and remove.

To weld on the 4 legs, first I propped up the pizza pan on the intake manifold at an approximate correct height, added the shaker to the top, and closed the hood. There, I was able to make fine adjustments to the height and alignment of everything. Once I was satisfied, I opened the hood, cut off some 1/8" flat bar stock with a hole drilled in one end, and tack weld the legs one at a time to the pizza pan--I mean, shaker base.  :lol:

With all 4 legs in place, I was able to position and mark the snorkel. Ready now to cut out a hole in the shaker base so the snorkel can pull air through.

Here's the welded-up shaker base, complete with snorkel and all four legs! It'll look a lot better once I smooth up the welds and paint the assembly. I'm thinking I'm going to mount a flat, round tray the same size around as the shaker base at the top of this base, right underneath the scoop, and use a jigsaw to cut a rectangular hole to install a modern flat-panel air filter, since this base is far too short to have room for the classic round filter like this car used from the factory.

Yes--I am aware that the turbocharger running at full-tilt on this particular engine may consume up to 1,000 CFM of air flow and there is NO POSSIBLE WAY to fit a 1,000 CFM air filter in that shaker base--but, I have a diabolical plan to solve that problem later on.  :cool:

Here's the final fit of the shaker scoop. It sits just about like it did on the 403--same height, same position. Not too high/tightly squeezed, so it's free to shake like it's supposed to.

Note: Hood not completely closed/aligned because there is currently no hood latch, and all of the body panels are basically hanging by a thread for temporary purposes.

Short video demonstrating the completed shaker and mount assembly shaking and moving along with the engine (barely perceptible due to having fresh, good motor mounts) like it's supposed to from the factory. This video is intended to go along with the few pics I posed earlier in the day detailing the build of the home-made shaker base.

Very sneaky--looks totally stock so that you'd never know there's a 500 HP turbocharged engine under the hood.  :cool:

I'll be quite excited when I finally get all the plumbing complete to get the scoop actually feeding the engine.


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At last, the tailpipe assembly is FINISHED! Pictured here is actually three separate pieces, all attached with V-band flanges, so that it's easy to install/remove each individual pipe to make working on the car easier. I also welded on four hangers to help support the weight of the assembly, and as per the usual, I used high-temperature exhaust paint to clear-coat over the welding seams so they don't rust. Miraculously I managed to meet my goal of mandrel-bent 4 inch pipe all the way from the turbo to the rear axle, then split into two mandrel-bent 3 inch pipes with NO ground, tire, body, or spring clearance issues! The fitment isn't 100% perfect, but the issues are minor and it wouldn't bother someone who isn't a perfectionist.

The tips I used here are made by Pypes, and look just like the stock ones but they're MUCH larger at 3 inches to allow the turbocharger to breathe well.

The completed exhaust system--view of the tailpipes from each side and the rear, and underneath showing the routing and amount of ground clearance I was able to achieve despite running 4 inch pipe the length of the car.

Thankfully the awesome sound didn't change with the installation of tailpipes--it just eliminated the jarring drone from inside the interior.

So the good news is I finally got around to replacing the broken fuel door.

The bad news is that now that the fuel door is new, it REALLY shows how bad of shape my tail light lenses are in... I definitely did not realize that. I'll try to fix that, because this looks pretty horrible.

I took off the tail light lenses one at a time and took them apart. They are two pieces--the lens (top) and the smoked cover (bottom). I won't need to touch my lens as it's in good shape--I'll just need to apply some new paint to the smoked outer cover. The whole thing doesn't get painted--only the tops of the "steps" that are molded in to the piece.

Closeup view of the smoked outer lens, showing that there's clearly no black paint left. This will be time consuming to mask off properly.

Apparently it is downright impossible to find 1/2" wide masking tape locally--maybe I'm just looking in all the wrong places?

Well, anyway, I used 3/4" masking tape, then used an X-acto knife to cut each piece of tape to size. Most of the outer lens gets masked off, because we only want to paint the tops of the steps.

Here's the outer lens with the new coat of black paint applied to the tops of the steps. Hard to tell now, but once it's back on the car, it'll give the tail lights a much more "blacked out" appearance.

Here are both tail light lenses after removing, re-smoking, and reinstalling. These turned out great! Now, they match the new fuel door and the rear of the car doesn't look so terrible.

Since I'll have working AC now, I decided tinting the windows would be a good move. I used pre-cut tint, and tinted the left and right window. I left the back window alone since it has a louver and shouldn't matter much. I used 35% tint.

Also pictured here: I replaced my sail panel decal, finally after 8 (?) years or so. I was on my way to Boone, NC one day and somebody tried to pass me while I was signaling and turning left, so they smashed the rear quarter panel. The body shop had to remove this decal to repair and fix the area, and I had never gotten around to replacing the decal on this side. Well, it's back now.

I re-finished and reinstalled the rear window louver. It was getting in pretty rough shape with all the paint flaking off.

I replaced the driver door handle--the old one broke in half on me one day when I tried to open the door on a cold morning. This isn't how it'll look completely finished--I still have to paint the inside of the handle red and apply the "4-wheel disc" decal.

I also replaced the driver door latch after this door has refused to open on me just one too many times. Once in college I pulled and pulled and pulled on it after class to no avail, had to call the police to come open the door for me and of course, when they got there, it just opened right up like nothing was wrong. Then, the week we moved, the door was stuck again and I had to crawl through the passenger side and repeatedly kick the door from the inside to open it.

Hopefully no more.

I removed each wheel, cleaned off all the brake dust, polished the rim and the outer face of the spokes, then PAINSTAKINGLY masked off each individual polished spoke face, and trimmed the masking tape away from the recessed areas with an X-acto knife. It's a bit hard to distinguish in the photo, but the recessed areas are painted and the rest is polished.

This car had what appear to be original--or at least very, very old mud flaps on it when I got it. I have searched high and low, and found evidence they existed, but was not able to find any reproductions of those mud flaps. So what I did here was just ordered some really oversized big truck mud flaps made out of the correct material, and used a Dremel cutoff wheel to cut them to the proper shape and size using the originals as guides. Then I added screw holes in the correct locations using a drill press. Lastly, I attached these laser-cut stainless steel birds I procured from eBay using rivets. They don't look original at all--but they do compliment the car well and look very nice. I was inspired by a similar design someone else had done online--though I opted to rivet the birds on mine rather than glue.

Here's a shot of a newly refinished wheel installed along with one of my custom mud flaps. Each corner of the car now looks just like this one. Much better!


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With the fuel pumps and sending unit tested and working and everything in the fuel system leak-free, I was finally able to seal up and install the cover for the access hole I made in the trunk. Made the fuel pumps much quieter from the inside!

Got both the front speaker and subwoofer amps installed in the deepest part of the trunk, where the spare tire will ultimately conceal them.

This is the light-duty air compressor that will feed the domes on the wastegates and allow the computer to have complete control over how much boost the turbo will supply. The plumbing was somewhat complicated, and includes a cutoff switch for the compressor motor, a regulator, a gauge, and a filter/water trap. It's all put together now and ready to install in the car.

(Sorry about the dark photo)

I got the compressor tank all aligned and mounted to the floor. I'm going to give more careful attention to the compressor motor, since it's a bit loud and obnoxious and I want to do all I can to help keep it quiet.

Here's the anti-vibration mount I came up with for the compressor motor--it's 3/4" OSB with two layers of rubber isolators. This will bolt to the trunk floor and then the compressor bolts down to the rubber isolators. Then, I'll enclose the entire assembly in a 3/4" OSB box to further kill the noise.

Here's the finished compressor, with the motor mounted to its anti-vibration mount. Ready to build the enclosure now.

I used cardboard to cut out a rough shape of the trunk in this area, and then cut two pieces of 3/4" OSB to help contain the noisy air compressor. This will later be covered in carpet and made to be easily removable so it looks better.

I wasn't 100% sure where to put the subwoofer, but I eventually decided it would be an efficient use of space to use the air compressor enclosure as a subwoofer cabinet also--so, I cut a subwoofer hole in the 3/4" OSB in a location that's clear of the compressor motor.

Here's the compressor enclosure/subwoofer cabinet roughly mounted in the car. All that's left for this piece is to create mounting points and cover it in carpet. I'll probably save this step for last, and carpet everything all together.

I plan to put a thin, carpeted wooden cover (1/4" plywood) over the battery box to make things look cleaner in the trunk--so I installed these long 1/4-20 screws into the battery box lid to give the plywood somewhere to mount to.

Last bit of cleanup here in the trunk was to label the fuse panel cover and install it. Ready to cover all this up with carpet now!

Trunk is all carpeted!

Got the subwoofer and air compressor enclosure all covered up nicely, the subwoofer is hidden so you won't see it unless you know to look for it. I chose to use the big plastic thumb wheels to attach my beauty panels so it looks like something the factory might have done.

Here's an overall shot of the completed trunk with the spare tire installed. You can see the fuse panel and battery box are now hidden, and I also made a 5-piece wooden panel to cover up the area behind the tail lights. The few wrinkles you see in the carpet are actually the fuel system wiring laying under the carpet--it's really stuck down tight and smooth!

I'm quite happy with how the trunk turned out. If I need to change the battery or inspect my fuses, it's as easy as removing the two plastic thumb wheels pictured here on the battery box and removing the carpeted panel. The big orange switch is the "kill everything" switch for the battery, and the red and black posts are always hot and used to jump-start the car or charge the battery if needed.


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Installed the three turbocharger gauges into a pod, and these will go in the map pocket on the center console. There's a gauge for boost/vacuum, air/fuel ratio, and fuel pressure.

Here's the back of the turbo gauge assembly. These gauges are pretty neat--they require the Holley computer to operate, and the connect using only a single power cable and one headphone cable. The three gauges daisy-chain together and only one connection is required to the ECU. They operate off of a CAN-BUS type connection.

Here is the center console all re-installed in the car along with the three turbocharger gauges.

They don't make a gauge pillar pod for these cars--not 100% sure why, but they sure don't. So, this one is a 2-gauge pillar pod for a fox-body mustang. See how nicely it fits with zero modifications? All I did was screw it on and paint it and it looks like it belongs there.  :D

On this pod, from left-right and top-bottom:
-Warning LED
-Caution LED
-Transmission pressure gauge
- High-beam indicator
-Traction control toggle switch
-Cruise control indicator
-Transmission temperature gauge

Just another shot of the 2-gauge pillar pod installed, taken from a little different angle. Blends in great!

Steering wheel is all reinstalled with a new, working horn button. Now when I move it around the yard, the steering wheel won't come off in my hands, which is a plus.

Finally got the door panels re-installed.

...and finally, the entire interior is all back together. At last, it looks like a car again (at least on the inside) instead of a shell.


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Something this car has never had since I've owned it--the fiberglass underhood insulation. I decided to install this so the hot turbo components don't cook the paint or decal on the hood. I did have to cut out two small spots and seal them up with heat-reflective tape for clearance--there's two places on the turbo system (the top of the crossover pipe and the passenger wastegate) that come within a gnat's hair of touching the hood. It's nothing short of a miracle that all this fits underneath the hood at all.

I also replaced both windshield washer nozzles on the underside of the hood (the car only had one remaining and is supposed to have two). This is yet another feature that the car has never had working--the windshield washer system

Here's the passenger side windshield washer nozzle, complete with a new hose.

Installed a new windshield washer pump onto my existing wiper motor along with all new hoses. Looks much better! It'll be cool to have a working windshield washer again.

On to the front end of the car.

Here, I'm drawing out where to cut, drill, and bend to make fan shrouds for the engine oil and transmission fluid coolers which will be mounted to the left and right of the radiator. The computer will have independent control over each to hopefully maximize the car's cooling capacity.

Here's one shroud all cut out, drilled, welded, painted, and weatherstripped (to help the fan seal as well as possible). There will be two of these, each nearly identical.

Here's the transmission cooler with the shroud and fan installed. The engine oil cooler will have an identical setup.

Here's a photo of the completed core support, with annotations to show all the modifications that were necessary to make all my plans work together. Pictured here is the front of the core support that would face the road as you're driving.

Here's a shot of the rear of the completed core support, with the transmission and engine oil coolers installed. I've also labelled this one to help show the modifications that weren't visible in the previous photo.

Here's the core support with the A/C condenser and turbo intercooler--which I've painted black with a very thin coat of lacquer to disguise it--installed. The two pipes curve around the core support and one will connect to the turbo outlet and the other to the engine intake. I stopped here and performed a leak test on the joints so far with compressed air to be sure I had no leaks that would be difficult to fix later.

Here's the engine side of the core support, showing the turbo plumbing installed. This rather heavy core support is now ready to be installed on the car.

Core support is installed! Ready to start connecting the cooler, turbo, and A/C plumbing, and install the radiator and fans.


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First up is the transmission cooler and wastegate compressor plumbing. I made up these braided stainless (for the transmission lines) and braided black nylon (for the wastegate compressor) lines which will run inside the passenger fender from the firewall to the components they connect to out on or near the core support.

The adapter laying in the center there is for a temperature sensor, so the computer can monitor the transmission fluid temperature going into the cooler and control the fan accordingly.

Here are the braided lines installed, hidden away between the outer fender and freshly-painted inner fender. They will be all but invisible when the project is finished.

Here I've installed the A/C filter/drier using big hose clamps to attach it to the funny looking bracket I welded on to the core support (hopefully that weird design makes sense now). I used my A/C hose crimping tool to crimp an end on the hose, and then used an SAE-Metric A/C adapter to install a GM A/C pressure sensor from a 2001 Chevy truck onto the filter/drier.

Why do this when Vintage Air includes their own sensor/switch?

I want to wire the A/C system in to the Holley ECU so I can monitor the pressure, and give the engine computer some control over the A/C--like when I go full throttle, disable it, and if the car's overheating, disable it, etc.

Pulling a vacuum on the now-complete A/C system.

The A/C appears to be sealed up pretty tight--after days of sitting, it's still holding near 30 in. hg. of vacuum. Looks like it's ready to charge up, wire up, and test as soon as the radiator and fans are installed!

Here's my radiator and electric fan setup.

The radiator is for a stock '79 trans am without the heavy duty cooling. I chose this one because it's THIN and gives me the most room for the turbo components--I hope this doesn't come back to bite me later--we'll see. This car will NEVER see a race track, so I'm hoping this will be sufficient for street driving. It's a single row of 1-1/4" aluminum cores. MUCH lighter than the original copper/brass unit the car came with.

The fans are off of a 2000 Ford Windstar minivan (they're brand new), and the fit the radiator almost like they were designed to. I only had to trim two plastic ear things off each side due to interference with the turbo pipes and steering box, and had to enlarge the opening around the water outlet at the bottom. These fans move a CRAZY amount of air on high for something stock--they'll just about levitate themselves off the ground while running if laid down flat.  :shock:

I sealed the shroud to the radiator with rubber weatherstripping and rubber strips.

I used a universal top radiator mount to hold the radiator in place, since the stock upper radiator mount was part of the stock fan shroud (which was made for a mechanical fan) and I didn't really want to cut up my nice, stock fan shroud.

I'm really proud of this. I got the idea to mount the radiator overflow can between the front bumper and the core support, getting it out of the engine bay complete, and making it nearly invisible so the eye is drawn to the engine instead of all the junk on the fenders, etc. This worked out great and shockingly fits without the need to grind or modify a single thing! It looks so good, in fact, that I decided to put an identical tank on the other side in this same location and use it for the windshield washer fluid reservoir.

Nothing you buy today ever seems to be made well...

The overflow tank (and windshield washer fluid tank) are no exception. I mean, they ARE built very well as far as being nice looking, well-sealed, and sturdy--but that's part of the issue--they're TOO well-sealed--there's NO vent!! HOW are these supposed to work then they're sealed up tight enough to serve as a compressed air tank??

Oh well, nothing a very small drill bit and the drill press can't fix...

What really cracks me up is that recently at a car show I saw another car with an LS swap--with this exact same tank--and they ALSO drilled the exact same hole in the exact same spot!  :lol:

Testing the now-functioning windshield washer pump, nozzles, and reservoir. They work great!


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With the radiator all in place, I was able to charge and test the A/C. It blows cold after working out some fan control logic kinks in the Holley ECU (my fault, I was the one who programmed it).

Here's a graph of the A/C pressure while the car is running. The red square wave shows the ECU commanding the A/C compressor to cycle on/off as the pressure changes, and the blue line is the pressure going up and down as the compressor runs.

This graph was made before I made the final tuning adjustments to the A/C system, so it's actually a lot smoother now with less peaks and valleys.

On to the other side of the core support--the engine oil cooler.

Initially, I had purchased a thermostatic sandwich adapter to go between the oil filter and the engine to help the engine oil reach a good operating temperature before being sent to the cooler. Summit's website confirmed that the adapter would fit this 5.3 block--WRONG! It was miles too big around, so I had to send it back and order this here.

This is a very nice oil cooler adapter that bolts on to the factory oil cooler location on the side of the engine block, just above the oil filter. The oil pressure sensor screws into the top--which is fantastic, because that's where I have the oil pressure sensor wires run to already. This block will let the engine oil warm up to 212 degrees before sending it out to the cooler.

Here's a shot of the oil cooler adapter installed along with the braided stainless hoses which run out to the cooler on the core support, and the oil pressure sensor. Just like on the passenger side, these hoses are hidden between the inner and outer fender.

While I was running wires inside the driver fender, I took a moment to wire up my front wheel speed sensor. This sensor will be used by the ECU for traction control when I engage the traction control toggle switch. The idea is that the computer can compare the front and rear wheel speeds to detect a loss of traction, and remove boost and/or timing until the car hooks up, slowly adding both back.

This picture is of the back of the brake rotor, and the arrow points to the cast-in features that I'll be using to trigger my magnetic speed sensor. I feel fairly safe basing my design on this feature, as I looked up replacement rotors from a few different parts suppliers, and it seems all had whatever these ribs are cast in to the backs of them.

The arrow here shows where I installed the magnetic wheel speed sensor in the brake dust shield. I tested everything, and it works! It shows speed on the graph as I rotate the wheel.

I decided to upgrade the headlights to something a bit more modern. I will be replacing the stock sealed-beam halogen headlights (left) with a modern H4 system (right). Those, coupled with the new direct-to-battery 12 gauge wiring and relays should be LOADS brighter than stock.

In order to make the new headlights fit, some slight modification was required to the headlight bracket. The bucket on the bottom is stock, and the top one I've opened up a bit with a Dremel tool. The backs of the H4 adapters are significantly larger around than the stock bulbs--so more room was needed to make them fit.

Here are the new H4 headlights assembled in the freshly painted bracket, ready to be installed back into the bumper.

The horn bracket is now ready to be re-installed.

To make this piece fit with the new intercooler, I just had to cut apart the bottom of it and weld in about a 1-1/2" long extension. Other than that, everything fits great. Simple modification.

Horn bracket is installed along with two new horns, as the old ones were sounding quite weak.

Also pictured here is the completed front wiring harness. This was the last of the wiring needed to complete the car. Now ready to reinstall the front bumper!

Front bumper crash support has been repainted and reinstalled.

The hood latch and release cable are ready to be reinstalled now.

This ugly mess of zip-ties and hose clamps is my answer to the past two hood release cables I've had on this car breaking apart where the cable meets the latch. The cheap plastic sleeve just splits open and compresses when opening the hood, preventing the cable from pulling far enough to do anything and requiring me to reach my arm under the front bumper and pop the latch by hand.

Hopefully, the hose I've slipped over the cable here at that weak spot and reinforced with clamps and zip ties will prevent that from ever happening again. I don't even care how bad it looks as long as it works.  :-P

I bought a front grille kit for the car, as the car has never had front grilles since I've owned it, and it came with these nice looking replacement parking lights!

That's my old one of the left (obviously). It had seen better days.

Here are the new parking lights installed into the crash brace.

I did have to shave just a HAIR of metal off of one of the crash brace brackets to make room for the A/C filter/drier, pictured here. Amazingly, that was the only modification to the front end (other than extending the mount for the horn bracket) required to make all this stuff fit.

Time to install the front chin spoiler.

It ALMOST went on perfectly just out of the box--but, there was one area where it was supposed to bolt to a hole on the horn bracket--and since I extended that bracket, the hole was out of reach, and the bracket itself interfered with the chin spoiler. So, I had to take a Dremel tool and just slightly notch out the chin spoiler at this location. You can't even tell it's been altered unless you crawl under the car and look.

Here's how well the chin spoiler ended up fitting after notching it to fit to the altered horn bracket.

Bumper is back on! Finally, looks like a car again!

For the first time since I've owned the car, it's got front grilles. Looks much better!  :grin:

Here's the extended horn bracket haunting me again...

Extending the bottom of the bracket brought the top of it in closer toward the engine--so I had to add these stacks of washers between the bumper and bracket to make everything fit. If I leave these out, the bumper draws up to the car too tightly and the hood won't close.

Here's the front bumper 100% complete, and all the body panels attached and aligned. Progress!

The back of my hood has always been missing this chrome strip that the build sheet says it's supposed to have--when I figured out it was just plastic from the factory, I just went to the parts store and bought a roll of plastic universal chrome trim and added here. It actually blends in great!


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On to the turbocharger piping. I cleaned all the spatter off the two charge pipes, and painted both of them satin black. Ready to install!

The turbo compressor housing and its associated charge pipe (which is barely even visible in this photo--it's tucked underneath everything) fit great!

The other half of the charge piping that comes out of the intercooler, well, doesn't fit quite as great.

This shot shows the pipe is a bit too tall, and would cause the air to have to go over quite a ledge to get to the engine, posing a nasty restriction. Easy fix.

Here's the other problem with the other charge pipe--it hits the steering box adjustment bolt and rattles. Another easy fix.

Here's the fix for the inlet restriction--I just marked where the pipe extended too far and trimmed it with an angle grinder. Much better. Told you it was an easy fix.  8)

To fix the interference with the steering box, I just used a ball peen hammer to make a deep dent in that spot, and re-painted it.

I performed one final pressure test with compressed air before bolting everything down. This was successful--I found one or two small leaks fixed by tightening clamps, then one of my test plugs blew out and whizzed past my head like a cannon. After I changed my shorts I took that to mean the system was capable of holding pressure, and moved on.  :shock:

Here's the charge piping all connected up to the engine.

Wastegates are all plumbed up!

The top line goes to the boost solenoids, which in turn go to the air compressor in the trunk--and the bottom line goes to the turbo outlet. The two work against each other, and the ECU uses a pressure sensor to adjust the pressure and control the amount of boost being applied.

I wanted to add a personal touch to the engine and make it look a bit more like it might have been factory, so I used one of my old wheel center emblems and made a bird emblem to go on the front of the intake elbow. This is made out of a stainless zip-tie, some two-sided tape, and a piece of sheet metal.

Here's the home-made bird emblem installed on the engine. Looks right at home!

Next I began connecting up the vacuum hoses. I used hairspray and zip-ties to connect them, as I read that's best for holding them on a boosted application.

Two of the vacuum lines would have been quite long--so I fabricated some hard lines for those. I've pictured and labelled them here.

I fabricated an intake pipe out of 4" exhaust pipe. I've labelled all the pieces here.

The "Boost actuated secondary air filter valve" will connect to a second air filter that will be installed in the fender, and will open only when the turbo reaches 3-5 psi of boost. This is necessary because the shaker scoop alone isn't capable of flowing enough CFM to feed the turbo at full tilt.

Here's the basic idea of how the intake pipe is going to connect.

I finished all the welding on my home-made shaker base. The two bungs you see are: (top-left) for the PCV and (bottom-right) a water drain.

Here's the bottom of the shaker base, showing the notches I had to make in the outlet to clear the LS coil packs.

Next order of business is to make provisions for an air filter. I cut this round piece of sheet metal out, and it'll serve as a filter housing. This will be welded to the top of the shaker base.

Here's the completed shaker base, ready to paint, with the filter installed.

I'm not the biggest fan of K&N filters--but for something like this, it's okay. Besides--I could not readily find another filter to fit this particular application.

Shaker base is all painted and ready to install!

Here's the shaker base complete with filter installed and attached to the intake pipe.

Here's a shot of the PCV system--being a turbocharged engine, the PCV setup is mildly complicated.

The crankcase side is normal--it just connects straight to the air/oil separator.

The main vacuum line that comes out of the engine has a check valve on it to prevent it from being able to feed boost into the crankcase. From there, it's teed to the turbo intake pipe, right next to the turbo inlet. There's also a check valve at this location. The purpose of this connection is that when the engine is at wide-open throttle and the turbo is sucking away, this is the location most likely to be able to pull a vacuum on the crankcase. The check valve prevents this from being a vacuum leak until the turbo actually kicks in.

Here's a closeup of the air/oil separator and oil dipstick bracket that attach to the shaker base.

Here's everything with the shaker installed!

It's finally coming together! :-D


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The pictures are all working now! What a great build. It's been a long time since I went through all of your progress.  :cool:

1976 Trans Am LS1, 6 speed, C5 Brakes, LS1 rear 12" brakes, and much more...SOLD
My Build:

New project: 1968 Camaro LS6, T56, Speedtech, Hotchkis, DSE, Z51 13.4" front brakes, LS1 rear disks, etc.


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The pictures are all working now! What a great build. It's been a long time since I went through all of your progress.  :cool:

Thanks and I'm glad the pics are working--I still don't know what the issue was but glad they're working now!!  :grin:
I hated to see the database here crash--a ton of great knowledge will be lost, maybe someday at least part of it can be restored. I wanted to do what little I could to help rebuild just in case it can't.

I decided to put some decals/emblems on the intake pipe, since it was so empty looking. This really helped the look of the engine bay.

Why the "327" displacement, you ask, if this is a 5.3?

True, the 5.3 is only 325 cubic inches--but this one's bored .020 over. Technically that makes it a 328--but who's counting?  :grin: The 327 was the closest common displacement I could find.

I also added a "Trans Am" decal to the angled portion of the intake pipe, just to give it yet another "it might have been factory" type of touch.

Here's the flexible hose that connects the auxiliary air filter to the intake pipe.

While I was adding decals, I also added labels to my coolant and windshield washer reservoirs. They're on the edges, near the fenders.

Here's the new wiper blades and the plastic grille to cover the cowl are reinstalled.

You wouldn't know by looking there's a whole wiring harness and electrical center under there...  :cool:

As a final touch, I wrapped my vacuum lines in black nylon braid to make them look better.

I cut a leftover piece of black rubber and bolted it to the passenger fender to help cover some of the wiring and plumbing back there

DONE!!!  :D :D :D


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First short drive:
Uneventful, and thanks to a faulty camera mount missing half the footage.  :sad:

I did not want to "goose it" in this video due to too many unknowns, so the most I got here was about 35-40% throttle--so the turbo did not kick in here or anything exciting like that. Just wanted to see how it would do on about 1/4 mile of roadway.

The squeaking belt is OBNOXIOUS and it ended up being a faulty balancer which was manufactured slightly crooked. I replaced it with a Fluidampr and the squeaking hasn't been back since.

Still have some minor tuning to do--it has a big of a cold start problem in real cold weather. This log shows that. The square wave is the "starter crank" signal indicating the engine is cranking, the yellow line is RPM, and the other line is the air/fuel ratio. You can tell by the RPM that it has a bad stumble and stall when started in cold weather, and the air-fuel ratio line reveals why--it goes way lean as soon as it starts.

This table revealed which cells the engine was operating in when it was having the cold start issue, so I increased the fuel in those cells.

...and... that was it!

Here's another graph of a cold start from a different day--the fuel increase made all the difference in the world. It started the first time, and settled in to a nice air/fuel ratio quickly.

A mostly boring demonstration of how the car drives after the completed tune:

Is it possible to have too much power?  :shock:

Did a couple of runs up to 60 MPH, once with traction control off and once with traction control on. This is the log of the run with traction control off. Yellow is rear wheel speed, blue is front wheel speed.

Nothing but tire spin all the way up to 60 mph, when I finally let off. The oscillations are pretty violent wheel-hopping, no doubt a result of the stock rear suspension not being up to the task of handling ~300% more power than stock.

The end result of the non-traction control run. All the spring wrapping and wheel hop spun an axle tube and sheared my brand new Energy Suspension polyurethane axle-to-spring pads and allowed the axle to move crooked, which I promptly found after the car suddenly started tracking crooked like a crab.  :sad:

This was the run from a near stop to 60 MPH with traction control ON. MUCH cleaner, one spike when the transmission shifted gears and chirped the tires. The traction control program did great and keeping wheel spin down to a certain percent and propelling the 4,000 lb car from ~5 mph to 60 mph in about 4.5 seconds.

Another observation: with the turbo at full-tilt, the car gets about 1.5 GALLONS PER MILE (not miles per gallon)  :shock:. Impressive.

So, I had the axle tubes welded solid to the center housing, and installed a beefy rear diff cover complete with cross-braces. Additionally, I added traction bars. That will NOT be happening again!!

My impressions of the finished product:
Reliability has been flawless so far (almost 3,000 miles). I wouldn't be afraid to drive this car anywhere.

Power is GREAT and comes on like a freight train once the turbo starts spinning. I estimate about 500hp. Certainly all I need and more than I can really even use on the street so no complaints whatsoever. I can break the tires loose on a roll and spin up to 70mph if I want to--that was alarming the first time it happened!  :shock:

Gas mileage exceeds expectations even in my wildest dreams!! I average about 24 mpg in mixed cruising between highway and city, I've made 3 highway trips so far and got 28, 28, and 32 miles per gallon each trip. No one ever believes me, so I took pictures of the odometer and the fuel pump after filling up during one of the 28mpg runs  :grin:

(This was after running 70mph on the interstate for 2.5 hours running the A/C)

It's sneaky. No one suspects a thing. At car shows and cruise-ins, the most common reaction is [walk past car], [look back at engine], [walk back to car for closer look]  :lol:

The A/C blows cold. I don't seem to have any temperature issues, either, as the car averages running 180 degrees with the A/C on on a hot day cruising down the interstate, and about 190 in stop-and-go traffic under the same set of circumstances. The only thing I can think I might do differently on this swap if I were to do it again would be to do it sooner!  :lol:

10/10. Would recommend a turbo LS swap.  :grin:


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What software did you use for those videos where you've added gauges?

1976 Trans Am LS1, 6 speed, C5 Brakes, LS1 rear 12" brakes, and much more...SOLD
My Build:

New project: 1968 Camaro LS6, T56, Speedtech, Hotchkis, DSE, Z51 13.4" front brakes, LS1 rear disks, etc.


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What software did you use for those videos where you've added gauges?

It's a software called RaceRender 3. I understand it's made by HP Tuners, but the data files that the Holley ECU exports also work very well with it. I got the paid version because I needed more timeline segments and text overlays than the free version allowed, but they offer a free version as well (I'm in no way affiliated with the product or company of course but it worked well for me).

Here's the link where I found it:


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Congratulations on getting her running.  It sounds like everything is working good and you have a lot of power.  I had my axle tubes welded when I had the pinion seal replaced because I heard they can spin even in a stock setup.

I have read your entire new build thread.  It is a lot of work to re-create but shows you did a lot of work.  I think your welding is fine and was a great asset for your project.  Turbos will have a lot of piping and you were able weld your own custom piping.

Like me, you are definitely and out of the box thinker.  The pizza pan for the hood scoop was and example but there are many others.

Thanks for sharing.
« Last Edit: June 12, 2021, 02:42:06 PM by MNBob »
1979 TATA Extreme TKO .64
Hedman elite; Pypes 2.5; Borla XS; MSD 6A; Performer intake; open scoop; Sniper QJ;  110 Amp Alt; 4 core radiator/Mark VIII fan; RobbMc mini starter; subframe connectors; solid body mounts; fiberglass rear springs; poly sway bar and link bushings; 81 master; D52’s; Blazer disks; 225/60 & 235/60 17's TrueContact's; relays for PW, PDL, lights; keyless entry


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Congratulations on getting her running.  It sounds like everything is working good and you have a lot of power.  I had my axle tubes welded when I had the pinion seal replaced because I heard they can spin even in a stock setup.

I have read your entire new build thread.  It is a lot of work to re-create but shows you did a lot of work.  I think your welding is fine and was a great asset for your project.  Turbos will have a lot of piping and you were able weld your own custom piping.

Like me, you are definitely and out of the box thinker.  The pizza pan for the hood scoop was and example but there are many others.

Thanks for sharing.

Thanks so much for the kind words!! My welding has actually ended up pretty decent since surviving this project  :grin:  I've welded up several fairly heavy-duty farm tractor parts since this project got done that are still alive so I'm happy with that.


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