LS376/515 swap in a '78 Trans Am

[skisix38off]

I've started my journey into the LS swap area.  My Poncho 400 is made of good parts and has done a great job of taking me this far, now it's time to get some good power to the ground and to make the car more reliable.  I bought a GM Performance Crate LS376/515 - this is an LS3 with the LSA Racing cam in it bringing it to a rated power of 533hp and 486tq.  It has 871 heads and the Victor Jr intake manifold as opposed to the typical MFI black plastic intake.  I want this to work with my shaker and while I could develop a way to mount my shaker with the plastic intake, I just want to keep my shaker functional without fab'ing something up.  I will also be using a Holley Terminator LS system to control the ignition and provide Fuel Injection.  I am looking forward to all the benefits of FI on this car and to have the computer make the adjustments to keeping it running well and me not having to guess at which secondary rods to use and all the other stuff associated with maintaining a premium tune. 

I have bought a new LS conversion radiator to keep it cool and will use 4th gen dual electric fans controlled by the Terminator system.  I went to BRPHotrods.com to get the engine mounts and trans crossmember for the T56.  The T56 is going to be rebuilt to handle the new power/torque.  And I also purchased a AutoWire harness to go to the terminator system and to feed the Dakota Digital gages.  I bought a new fuel tank with in tank pump to supply fuel. 

At this time I will use the supplied exhaust manifolds and fab a mid-pipe to go from there to the current exhaust.  As part of this change over I will also go to a 4 link in the rear to handle the new power- those leaf springs don't stand a chance!

The new crate engine arrives!




I think that Victor Jr intake looks great!


Out of the crate and onto a stand.  I have to do this step because the LS376 comes with an oil that doesn't work for 2nd gen F-bodies, and I am installing an Improved racing oil pan baffle to help ensure that the engine is always supplied with oil.


Now for the Current set up...












Soon, the transformation will take place.  I am hoping to have it driving again in early Feb., 2019.

Pit crew and security crew! 

[Steve B]

Good luck with the swap.  I think the dogs might need to be put to work to help out.

[ryeguy2006a]

Looking great! you won't be disappointed with the LS motors. My dad just picked up a Terminator kit recently and we're looking forward to installing it on his 1971 Chevelle with a 496 BBC. Keep us posted!

[skisix38off]

I had to do a few little custom touches this weekend. 







I also received and installed my Improved racing Oil Pan Baffle to help keep the oil pick up covered in oil even on high G corners.  This is a nice piece. I also got my 4TH Gen Oil pan to install it in. 

[1979 Black and Tan]

very nice..is there a reason you went with a carburetor and not with the fuel injection that usually comes with these GM engine packages?

like this one

https://www.chevrolet.com/performance/crate-engines/dr525-muscle-car-oil-pan

[skisix38off]

More goodies arrived!

[skisix38off]

very nice..is there a reason you went with a carburetor and not with the fuel injection that usually comes with these GM engine packages?

like this one

https://www.chevrolet.com/performance/crate-engines/dr525-muscle-car-oil-pan

I was originally going to buy the engine you linked above.  There are several factors involved in my case, cost and availability, and it's very important to continue using my shaker.  The more I get into this though, I am so glad that I made the decision I did.  See below...











I do have fuel injection!  I will have all the conveniences of FI and all the performance advantages of FI.  And this system allows a DIY'er like me install anLS engine just like it was any Pontiac engine and this route is $2000 cheaper.  The Terminator LS system will also allow me to go to Multi-Port in the future if that's what I want.  Most of all, I believe the air cleaner, thus shaker, will fit right on top!  Then, there's the cool factor when the hood is up.

[ryeguy2006a]

Great choice! I will be helping my dad install his Terminator EFI this winter too. Hopefully tearing up the streets this spring! Keep us posted on your progress.

[jonathonar89]

Exactly how I think shaker T/A guys should be doing their LS swap right here.  950cfm 4 Barrel

Good stuff.

[1979 Black and Tan]

this looks amazing....

[skisix38off]

Steam vents????  Can someone chime in on this?  This is a detail about LS that I have read as being very important, how does it get connected?  Part Numbers?

[Updated71]

Mine is T-ed into the upper radiator hose similar to how it was done on some LS based GM trucks.  I haven't had any issue using this, but have not had an opportunity to do any type of competition such as your car sees.  I am using a transition from jagsthatrun.com.  https://jagsthatrun.com/collections/cooling-systems

I have a 17 SS and the line is attached at the top of the radiator just above the inlet for the upper radiator hose. 

If you decide to run an expansion tank, it may have a dedicated provision for this line.  C & R Racing tanks do.  Some find factory tanks at the junk yard and use them. 


The earlier LS motors had 4 ports all tied in together from both the rear and front.  I believe it was to prevent a particular piston or pistons from overheating.  At some point, only the front ports were open and required venting. 

[skisix38off]

Do I have this correct?

[jonathonar89]

Do I have this correct?

Yes

[Updated71]

At the rear of your picture, the part that is just off center of the intake is the oil pressure sender.  The port on the drivers side valve cover is capped off on my 11 production engine (Corvette based) and on my 17 SS.   Some use these ports for catch cans/oil separator. 

The front PCV port can be tied in after the MAF to keep it cleaner from oil.

[ryeguy2006a]

Yes, Updated71 is right the port on the rear of the valley cover is for oil pressure.

[skisix38off]

Not much progress in the last week...

I did a little bit of visual progress work.  I wanted verify that the air cleaner assy would actually go on the Holley and it does so, now, I just have to determine where the engine will sit in the engine bay and if the shaker will poke out in the same spot as the hole in the hood.

I also got the harness out from the Holley to start figuring out where things go.  The harness is very well done.  To me, without reading any instructions, I'm wondering how I will get the Crack sensor to connect and a few other sensors as well.

Another question for you TA guru's that have done several projects like this.  I bought an American Autowire update kit, the one to make the car work with an LS.  Does anyone have any tips for installing this kit specifically, or installing a new wire harness in general?  I'm thinking that getting the engine out and having some room to work will be a good thing.  How about the dash?  Remove the dash and then just take everything out?

[Updated71]

AAW makes a great harness.  You will need their crimpers.  They provide fused power for a fuel pump, keyed ignition (2), constant 12v.  I didn't use a Holley harness, but on the harness for engine management I did use (Speartech on one install), I was able to by-pass the Speartech fuses and wire directly to the power wires AAW provided.  It gave a much cleaner look similar to what the factory would have done.  I also bought some extra connectors and terminals that I used to wire other things so that every wire was a plug in connector. 

Rewiring the car will take quite some time to make sure everything is neat and laid out correctly.  It's actually one of my favorite parts of working on a car.  I also added mesh loom and heat shrink tubing on some of the parts of the harness for a cleaner look. 

Other than their crimpers, which are avilable for rent through them, I use a Power Probe (great tool to have), good wire strippers and a terminal removal kit.  The terminal removal kit comes in handy if you decide to add the mesh loom and shrink tube the ends for a finished look.  It also will help you remove some of the terminal bodies from your old harness.  They clean up easily and you won't have buy them.  You would just need more terminals. 

They send practice terminals and you should practice on them if you've never worked with Packard 56 terminals before.  Some may need a run over a file at the locking tab for a good fit.  There are videos on line that show this.

One place I added connectors was at my aftermarket gauges.  Another was at my electric trunk release. 


Excited to see how the shaker fits.  I used a Holley system many years ago when they still used dip switches for adjustments.  It still did good for how little adjustability was built in. 

[ryeguy2006a]

To answer the question you had about the crank position sensor, I think it would depend on what kit you bought. My dad just bought a Terminator kit recently and it was meant for traditional SBC/BBC distributors and the computer just needs a signal from the tach to know what the engine speed is. If you bought the kit with the injectors and such in the TB, I think you may need another harness that integrates for the LS motor, then use the TB for things like the TPS, IAC, MAP and etc.

Also, regarding the Packard 56 Terminals after a ton of research for a cheaper alternative to the AAW or Waytek crimpers I found that a cheap ratcheting crimper on ebay for $15 bucks that does a good job with the Packard 56 Terminals. I can get a part number when I get a chance if you are interested. They do need to be modified slightly as the jaws are slightly too wide and distort the terminals.

[skisix38off]

Thanks for your comments.  I will need to look into those crimpers and get some practice in on them.

ryeguy - If you can get that number on those Ebay crimpers that would be great!  Also, I got the Termintor LS system, I hope that I don't need another harness to make it work.

[ryeguy2006a]

Here is the link to the ones that I bought. In my build I think I took some pictures of the crimps that it did. I need to get my angle grinder and shave a slight bit off the end so that it doesn't distort, but otherwise great. I will tell you it's a heavy crimp, definitely need two hands, but I'm thinking of adding a longer handle to get more leverage.

https://www.ebay.com/itm/Crimper-Crimp-Pliers-Set-0-5-35-mm2-Crimping-Tool-Kit-Ratchet-4-Spare-Dies-W-Bag-/172669726736?hash=item2833eaf010

[skisix38off]

More carnage going on in the Busted Knuckles garage!  I just wish that re-assembly was as easy as the disassembly!  I go the engine out, dash out, interior out and the dash harness out in 1.5 days.   I hope I can get it back in and all together in the next 6 weeks.



My son home from college helping out..

[Updated71]

What trans are you going with?

[scarebird]

Powerglide!





*runs away*


/you know somebody's done it...

[skisix38off]

What trans are you going with?

I've been running a T56 for the last year, and I love it!

[Updated71]

What trans are you going with?

I've been running a T56 for the last year, and I love it!

So you'll need to run the reverse light wiring, reverse lock out and speedo wiring depending on your gauge set as far as that area is concerned. How have you been running the reverse lock out until now?

[skisix38off]

I haven't had the reverse lock out wired in.  I have only been running the reverse lights, no lock out, no neutral safety... 

I have been making some slow progress, a lot of little things getting done.  I've had the engine in and out several times already just to find out how and where it would sit.  The T56 is out getting a Texas Drivetrain Performance upgrade to stage 3 so it can survive the new LS.  I'm very excited to say that this LS sits about 4" further back in addition to being a couple hundred pounds lighter the new placement will also increase it's balance front to back.

[skisix38off]

One of the things that will be coming out of the engine bay in this swap is the heater box.  What have folks done to get the blower to vent inside after removing the box?  I know there are companies like DSE that make the block off plate but, how does the blower get inside the cabin?

[scarebird]

I don't think you can - the fan sucks air from the windshield base, the output is ducted thru the engine compartment by the firewall duct.  You can use the side vent but of course need to be moving.

Some GM had power vents in the side plenums, maybe that is what you will need to mimic...

[skisix38off]

Help!  I fallen in Wiring hell and can't get up!!!!

There is a lot of wiring and initially it's intimidating but, after sitting with it and putting my hands on it several times and starting to map out where things are going and how they are routed it seems better.  Just waiting for a crimper now, should be here in a few days.

[FormTA]

I think that was my favorite part of the LS swap.

[Updated71]

I penciled in changes on the AAW instructions.  I also checked off each circuit as it was completed.  My car has no power windows or locks.  I used those for power for other things I needed.  There are a few wires that are just pass though wires at the bulkhead.  Off the top of my head, the tach and alternator exciter wires (white and brown IIRC) are 2 such wires.  If you don't need either, you can use those for anything else that needs to go from inside to outside of the car.  I'd have to look at my notes, but I believe I used those for fan trigger wires (dual fans).  My tach is fed from the PCM to a Speedhut gauge.

[skisix38off]

The engine is in, it may change slightly when the T56 gets bolted up next.  I decided to do some "motivation work" and skipped ahead a bunch of steps...









Question for you folks that have done this before...  What did you do with the water pump heater ports?  See below.

[FormTA]

I have seen others pull the pressed in sleeves and tap the hole for pipe thread and then use 90° fittings. My engine didn't sit back so far and just cleared so I lucked out.

[Updated71]

These L shaped hoses worked for me:




I added a bracket to the control arm stud and added a 2nd nut to hold it in place.  I don't have a pic of how it ended up, but here's one just to give you an idea.  I added adele clamps to hold the hoses in place loosely to allow for expansion.  I also rounded the edges of the guard.  If I find a pic, I'll post it:



Not sure if you have more clearance than I did when I ran this set up:

[scarebird]

45° fittings, pipe tap - male one end, female other, then 5/8" and 3/4"Ø nipples screwed in.

[skisix38off]

Thanks Guys!  I appreciate the response.  For what I do with my car, I want as much engine behind the front axle line as possible for weight balance.  For installation, I would have fewer issues to deal with if I picked the forward two mounts on the Muscle rod motor mounts.  Hmmmmm.....

[FormTA]

I figured you set it back for weight reasons.  I didn't even have to notch the frame for the alternator.  I used the dirty dingo motor mounts. AC is going to be a late 90s pump top mounted when I get to that point.

[ryeguy2006a]

Any updates?

[skisix38off]

It's been a while since any updates...  Partially due to having other things to get done and partially due to determining the best direction to go forward.  The holes in the K member located the tailshaft of the transmission about 2" off center line and had to be re-done, and since I was there already I just welded in nuts so that I don't have to dink around with the piss poor GM design of having a back up nut!  That's solved I played with the two positions the motor mounts can go in and, at least on my subframe, there were more changes to make in the forward position than the back position so back it is!  The cut out in the tunnel is nearly filled but the Direct Fit Muscle Rodz crossmember is not done as well as it can be.  They made it very strong but there is a flange in the front of the slot to bolt the trans to that would require lifting the trans 4" higher than it's working position and the clearance to the tunnel would be ridiculous.  So, I modified the crossmember and things are going smoothly again. 

I also got the front light harness terminated and in place.  With the way American Autowire does there kits, it's lost on me why they couldn't terminate the front lights and have everything in place so that it really was pull the old one out and install the new one.  The crimpers work great reyguy- thanks for that tip!

Promising Pictures next week.