Author Topic: LS376/515 swap in a '78 Trans Am  (Read 5433 times)

skisix38off

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Re: LS376/515 swap in a '78 Trans Am
« Reply #40 on: January 22, 2019, 08:09:58 AM »
Pictures!  Although, I don't think they capture the amount of work done...












Nexus

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Re: LS376/515 swap in a '78 Trans Am
« Reply #41 on: January 22, 2019, 10:55:11 AM »
Progress is the difference between visual progress where it looks like lots gets done with little work and actual progress where the hours put in go unseen as all you did was put in new wiring...how hard can it be?

lol...get work and keep ticking away at it...I look forward to more updates!!!
Charlie

79 Esprit but like many, it will be a T/A clone
(18 years and counting but still have her)

skisix38off

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Re: LS376/515 swap in a '78 Trans Am
« Reply #42 on: January 22, 2019, 02:38:41 PM »
I have been studying the wiring a lot ...  The Holley system has provisions to get engine temp and oil pressure so it can do it's job, what I haven't been able to find is how to get oil pressure and engine temp to the Dakota Digital VHX new gages.  I called both Holley and DD today to ask how they have done this in the past and was disappointed to hear each of them respectively pointing fingers at the other.  Both suggested that I use two sensors for each- one each for Holley and DD.  Surely that can not be a very good solution?  DD has an interface box, another $100, that is specific to the Holley EFI systems but, "they can't guarantee  that Oil pressue will go accross".

So, where are there other ports for engine temp and Oil pressure?  Isn't there Oil Pressure by the oil filter- I maybe just drill and tap for 1/4" NPT?  Also, any suggestions on pressure sending units for LS?  The Holley unit they told me to get is another $135!!!!  Who buys a $135 oil pressure sending unit?

FormTA

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Re: LS376/515 swap in a '78 Trans Am
« Reply #43 on: January 22, 2019, 02:56:14 PM »
I drilled the boss by the oil filter. I don't know what the LS3 has, you may need to get an ls1 version. I'll see if I can find a picture. I drilled the top of my water pump for my temp sending unit.
79 Trans am 301 (work in progress) LS swap n progress
79 Formula 301 (Work in progress)
67 RS Camaro (Work in progress)
See the recurring theme???

Updated71

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Re: LS376/515 swap in a '78 Trans Am
« Reply #44 on: January 23, 2019, 09:58:16 AM »
I initially did the boss by the filter too, but didn't like how close it put the large sender so close to the header tubing.  It definitely got quite hot.  I eventually moved it to the factory location on the valley cover using a T fitting I found on line.  One end is for the gauges and the other is for the PCM harness. 

This is the on line pic I used for reference.  I can take a pic of it on my car and get the fitting info if this is a direction you'd want to go. 

The surgeon general never said nuthin' 'bout smokin' the competition!

Re: LS376/515 swap in a '78 Trans Am
« Reply #44 on: January 23, 2019, 09:58:16 AM »

skisix38off

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Re: LS376/515 swap in a '78 Trans Am
« Reply #45 on: January 23, 2019, 03:32:56 PM »
I initially did the boss by the filter too, but didn't like how close it put the large sender so close to the header tubing.  It definitely got quite hot.  I eventually moved it to the factory location on the valley cover using a T fitting I found on line.  One end is for the gauges and the other is for the PCM harness. 

This is the on line pic I used for reference.  I can take a pic of it on my car and get the fitting info if this is a direction you'd want to go. 



I would appreciate that- I too am not wild about having sensors that low and right next to headers.

Thanks.

Updated71

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Re: LS376/515 swap in a '78 Trans Am
« Reply #46 on: January 23, 2019, 03:50:34 PM »
I did buy it from over seas.  It came very quickly though.    Approximately 3 weeks if I remember correctly.  Google the part number and maybe they are now available here.  Either way, I am pleased with the way this went. 


https://www.aeroflowperformance.com/af166-05-02s

The surgeon general never said nuthin' 'bout smokin' the competition!

Updated71

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Re: LS376/515 swap in a '78 Trans Am
« Reply #47 on: January 23, 2019, 03:56:30 PM »
Also, I believe I needed a slightly longer coupling for the factory sensor up top.  That was about $2 in the plumbing department locally.  The sensor is what is required for my Speedhut gauges.  It is a common early GM sensor.


The other part of your question was engine temp.  My Speartech harness gets temp info from the drivers side front of the head near the first plug wire.  I added the Speedhut sensor for my gauge to the same spot on the passenger side, but at the rear of the head (the heads are the same so looking at it from the passenger side puts that port opposite of the drivers side).  I had to remove a factory pipe plug and use a metric to standard adapter IIRC. 

I couldn't find a way to just use one sensor in either application.  They both use a different input signal to read correctly.
« Last Edit: January 24, 2019, 08:43:59 AM by Updated71 »
The surgeon general never said nuthin' 'bout smokin' the competition!

ryeguy2006a

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Re: LS376/515 swap in a '78 Trans Am
« Reply #48 on: January 24, 2019, 02:29:37 PM »
So, I understand why DD needs the oil pressure sender because that is what you will see on your cluster, but I'm curious why the terminator needs to see oil pressure? I don't believe that my dad's Terminator kit had an oil pressure sender in his kit? He had a fuel pressure sender in the kit. Is there an option with Terminator to kill the fuel pump if it doesn't see oil pressure or something?

On both of my LS swaps, I deleted the factory oil pressure sending units because they don't tie into the ECU. I have thought about wiring in a fuel pump kill switch inline with the fuel pump relay to kill the pump if the oil pressure dropped below like 5 psi.

1976 Trans Am LS1, 6 speed, C5 12.8" Brakes, LS1 rear 12" brakes, 17" Aluminum Rims, and much more...SOLD
My Build: http://transamcountry.com/community/index.php?topic=24465.0

New project: 1968 Camaro with 6?.?0?  5.3 w/ Z06 cam/T56
http://transamcountry.com/community/index.php?topic=74591.0

skisix38off

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Re: LS376/515 swap in a '78 Trans Am
« Reply #49 on: January 25, 2019, 07:50:23 AM »
A little break from wires..







jonathonar89

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Re: LS376/515 swap in a '78 Trans Am
« Reply #50 on: February 04, 2019, 09:51:12 AM »
Do you have any more pics of the Dakota Digital install?

skisix38off

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Re: LS376/515 swap in a '78 Trans Am
« Reply #51 on: February 04, 2019, 09:53:30 AM »
Do you have any more pics of the Dakota Digital install?

Not yet, soon though.  Are you looking for anything in particular?

skisix38off

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Re: LS376/515 swap in a '78 Trans Am
« Reply #52 on: February 04, 2019, 09:57:57 AM »
Moving back to the engine bay...  Spent entirely too much time, and time I don't think I had in order to be running for the March 9 Lone Star Good Guy's Autocross, on the inner fenders cleaning out the undercoating and filling holes.  With the new layout, there won't be any wires showing and the inner fenders are going to be clean- so I had to make them presentable....  That turned in to the rest of the engine bay and that consumed the entire weekend.  I have to say I am pleased with the result!







jonathonar89

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Re: LS376/515 swap in a '78 Trans Am
« Reply #53 on: February 04, 2019, 10:02:29 AM »
Do you have any more pics of the Dakota Digital install?

Not yet, soon though.  Are you looking for anything in particular?

Just curious to see how it mounts behind the dash bezel.

FormTA

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Re: LS376/515 swap in a '78 Trans Am
« Reply #54 on: February 04, 2019, 02:50:16 PM »
Were your gauge made from stock images or did you upload your own image. I like them, they look close to stock.
79 Trans am 301 (work in progress) LS swap n progress
79 Formula 301 (Work in progress)
67 RS Camaro (Work in progress)
See the recurring theme???

Re: LS376/515 swap in a '78 Trans Am
« Reply #54 on: February 04, 2019, 02:50:16 PM »



jonathonar89

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Re: LS376/515 swap in a '78 Trans Am
« Reply #55 on: February 04, 2019, 04:26:21 PM »
Were your gauge made from stock images or did you upload your own image. I like them, they look close to stock.

That’s the gauge setup from Dakota Digital.  Only comes that way.

FormTA

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Re: LS376/515 swap in a '78 Trans Am
« Reply #56 on: February 05, 2019, 07:09:59 AM »
Oh, for some reason I thought he said he was using speedhut sending units so I figured the gauges were speedhut too. They look nice. Thanks!
79 Trans am 301 (work in progress) LS swap n progress
79 Formula 301 (Work in progress)
67 RS Camaro (Work in progress)
See the recurring theme???

skisix38off

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Re: LS376/515 swap in a '78 Trans Am
« Reply #57 on: February 05, 2019, 07:18:28 AM »
Were your gauge made from stock images or did you upload your own image. I like them, they look close to stock.

These are Dakota Digital's VHX gages for a Pontiac.  They are close to the factory looking gages, not a re-done factory gage though.  I got new gages because:
1) I had to do something to get a speed reading.  The T56 only outputs a VSS signal, so I either had to buy a $300 adapter to go to the factory gage or buy a new digital gage to read the VSS signal.
2) With the new engine I wanted a more trustworthy reading of oil and water temp.
3) I wanted to be able to read the gages at dusk, not just full dark.

skisix38off

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Re: LS376/515 swap in a '78 Trans Am
« Reply #58 on: February 21, 2019, 08:20:24 AM »
I got a lot of work done- I just don't believe a camera will capture it.  I have all the wires connected that I'm going to connect right now- things like courtesy lights and glove box lights and cigarette lighter things I don't need to have done right now so, they are covered up.  The Dakota system is all wired and the Holley is all wired- just waiting for voltage.  I put a hole in the new transmission tunnel to run the wires from the trans to the dash, rather than running them thru the firewall, a cleaner install I believe.

I also ran the braided fuel line but didn't have the fittings I needed, or the regulator and filter to finish that job- I do now and hope to get that finished this weekend.  I also hope to get the exhaust finished so that I can power the system and if....  Big if, everything works and there isn't a bunch of smoke come out - I can start it!!!!!!!

Updated71

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Re: LS376/515 swap in a '78 Trans Am
« Reply #59 on: February 21, 2019, 09:14:45 AM »
Good luck!!
The surgeon general never said nuthin' 'bout smokin' the competition!

skisix38off

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Re: LS376/515 swap in a '78 Trans Am
« Reply #60 on: February 25, 2019, 08:11:11 AM »
A little more progress over the weekend.  I took Sunday off of race car building to go do some racing..  That was seriously fun and I was happy to catch up with a lot of the local people that I haven't seen in a while.














ryeguy2006a

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Re: LS376/515 swap in a '78 Trans Am
« Reply #61 on: February 27, 2019, 08:29:03 AM »
I'd say that's some good progress there! What are you doing for a fuel pump, regulator and etc.? Also, where did you get that overflow tank, I want one!

1976 Trans Am LS1, 6 speed, C5 12.8" Brakes, LS1 rear 12" brakes, 17" Aluminum Rims, and much more...SOLD
My Build: http://transamcountry.com/community/index.php?topic=24465.0

New project: 1968 Camaro with 6?.?0?  5.3 w/ Z06 cam/T56
http://transamcountry.com/community/index.php?topic=74591.0

skisix38off

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Re: LS376/515 swap in a '78 Trans Am
« Reply #62 on: February 28, 2019, 01:21:33 PM »
I'd say that's some good progress there! What are you doing for a fuel pump, regulator and etc.? Also, where did you get that overflow tank, I want one!

Thanks!

The fuel pump is in the tank and what came from Tanks Inc., for this conversion.  It's the 630 hp capable version.  The overflow came from Summit Racing and is a "universal" tank.

skisix38off

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Re: LS376/515 swap in a '78 Trans Am
« Reply #63 on: March 05, 2019, 07:46:38 AM »
Some more progress!  I have the exhaust tacked into place and it fits up very nicely to the floor - I'll have some ground clearance this year!!!!!
Also got a Hurst shifter for the T56- this shifter has a stud that the actual shift lever bolts to.  I want this because the location of the shift needs to be offset a bit to fit better in the  automatic console that I run. 








skisix38off

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Re: LS376/515 swap in a '78 Trans Am
« Reply #64 on: March 20, 2019, 07:19:41 AM »
I have enough together now that I have started to crank the motor with the starter - no gas because I don't want it to start until I see oil pressure.  Once I see oil pressure, I will connect the coil packs and put gas in and test/prime the fuel pump.

So, I watched several videos of how to prime the oil pump in an LS motor because I changed the pick up tube and pan.  I put slight pressure on the oil port on the side of the motor by the timing cover and I put around 2 quarts oil in that way.  After cranking in bursts of 10 seconds, about 6 times I still have no oil pressure and there isn't any sign of oil at the oil pressure port on the valley cover.  I will need to check to see if the oil filter is full, perhaps I didn't fill that. 






skisix38off

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Re: LS376/515 swap in a '78 Trans Am
« Reply #65 on: March 25, 2019, 07:04:36 AM »
So much for planning to start the engine this weekend!  After going thru a lot of trouble shooting with Holley Tech Services Sat.,  I boxed up the harness and computer to send back to Holley.  Seems the crank signal was grounded somewhere, could be the harness or the computer.  I got some other misc. things taken care of to stay on track moving forward.

Hopefully I get the parts from Holley Thursday.

Updated71

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Re: LS376/515 swap in a '78 Trans Am
« Reply #66 on: March 25, 2019, 09:28:45 AM »
That had to a pain.  I had a harness issue that took quite a bit of time to sort out.  In the end, pulling it and putting in another brand fixed an issue. 
The surgeon general never said nuthin' 'bout smokin' the competition!

ryeguy2006a

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Re: LS376/515 swap in a '78 Trans Am
« Reply #67 on: March 27, 2019, 08:21:59 AM »
What a bummer... My dad and I plan to install his Terminator kit sometime in the month of April. I'm hoping we don't have a similar issue.

1976 Trans Am LS1, 6 speed, C5 12.8" Brakes, LS1 rear 12" brakes, 17" Aluminum Rims, and much more...SOLD
My Build: http://transamcountry.com/community/index.php?topic=24465.0

New project: 1968 Camaro with 6?.?0?  5.3 w/ Z06 cam/T56
http://transamcountry.com/community/index.php?topic=74591.0

skisix38off

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Re: LS376/515 swap in a '78 Trans Am
« Reply #68 on: March 28, 2019, 07:26:23 AM »
In case this helps anyone else...

I don't fault Holley for this very much...  In my case, I followed the guide exactly, I went through the "wizards" to set a base program and the TPS autoset.  This made it look like everything was reading correctly - MAP, MAT, batt, etc...  When I cranked the motor though, there wasn't any rpm reading so that made it look like the crank sensor wasn't right.  Even after unplugging the crank sensor the rpm read 0.  This is why the Holley tech thought there was a short in the rpm signal - he said it should read "stall" or a value other than 0.

When I was wiring the system, there is a loose red/white wire and it was unclear to me if that should go inside the cabin to a keyed source or a always on source.  I called Holley and the tech told me that needed to be "always on".  So I connected it to the battery.  Well, the Holley computer doesn't save the calibration file unless the power is removed from that wire for 4 seconds.  Since I had it on the battery , when I turned the key off didn't make any difference.

Holley is overnighting the package to me and I will make that change and try again, hopefully with better results.

ryeguy2006a

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Re: LS376/515 swap in a '78 Trans Am
« Reply #69 on: April 01, 2019, 06:02:35 AM »
Very interesting, sounds like you have figured it out then. My dad and I have been working along on his install and we are hoping to test fire next weekend. I'll be interested to hear how you make out when you get the harness back.

1976 Trans Am LS1, 6 speed, C5 12.8" Brakes, LS1 rear 12" brakes, 17" Aluminum Rims, and much more...SOLD
My Build: http://transamcountry.com/community/index.php?topic=24465.0

New project: 1968 Camaro with 6?.?0?  5.3 w/ Z06 cam/T56
http://transamcountry.com/community/index.php?topic=74591.0

skisix38off

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Re: LS376/515 swap in a '78 Trans Am
« Reply #70 on: April 01, 2019, 07:25:36 AM »
Got the Holley stuff back and resolved an issue with the new AAW fuse box!  Now, things power up and shut off when they should,  I like that!
Still no running though- I'm a magnet for trouble.  I believe my fuel pump is bad and isn't putting out enough flow to make the kind of pressures the rest of the system needs.  That took a full weekend of troubleshooting.

I did get it to run very briefly by adding fuel manually- sounded great!

Nexus

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Re: LS376/515 swap in a '78 Trans Am
« Reply #71 on: April 01, 2019, 01:59:52 PM »
Right on...glad it fired up for you...very cool
Charlie

79 Esprit but like many, it will be a T/A clone
(18 years and counting but still have her)

skisix38off

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Re: LS376/515 swap in a '78 Trans Am
« Reply #72 on: April 03, 2019, 06:48:08 AM »
Fuel Pump!  I worked with Tanks Inc. and they were very helpful!  Their tech went through a bunch of tests they wanted me to do, most of which I already had results for, and then I just told the guy that what I really wanted was for them to send me a new pump.  The guy said ok!!!!!  They got it to me last night and the new engine is ALIVE!!!!  Sounds great too!
I know, worthless without video and I will get that this weekend, that's the next time I have available for it.  Time to get all the rest of the parts back on and make it a car again!

Nexus

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Re: LS376/515 swap in a '78 Trans Am
« Reply #73 on: April 04, 2019, 10:25:25 PM »
Fuel Pump!  I worked with Tanks Inc. and they were very helpful!  Their tech went through a bunch of tests they wanted me to do, most of which I already had results for, and then I just told the guy that what I really wanted was for them to send me a new pump.  The guy said ok!!!!!  They got it to me last night and the new engine is ALIVE!!!!  Sounds great too!
I know, worthless without video and I will get that this weekend, that's the next time I have available for it.  Time to get all the rest of the parts back on and make it a car again!

Its ok...we don't mind waiting for the video...a short while anyway...lol

super pumped its working for ya!!
Charlie

79 Esprit but like many, it will be a T/A clone
(18 years and counting but still have her)

skisix38off

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Re: LS376/515 swap in a '78 Trans Am
« Reply #74 on: April 05, 2019, 07:34:16 AM »
And the loooooooong awaited video!  So, at this point, the engine has run for maybe a total of 1 min in short 30 sec. spurts.  There's a lot of tuning left to do, I just didn't get to it all during this run, maybe another 5 minutes.  Runs by itself now that I can get the rest of the car back together - full interior, trunk, dash, and the brake booster and plumbing all need to go back in.

https://youtu.be/vKPaS3YqzGQ

ryeguy2006a

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Re: LS376/515 swap in a '78 Trans Am
« Reply #75 on: April 05, 2019, 03:50:59 PM »
Congrats! We're hoping to start my dad's Chevelle this weekend.

1976 Trans Am LS1, 6 speed, C5 12.8" Brakes, LS1 rear 12" brakes, 17" Aluminum Rims, and much more...SOLD
My Build: http://transamcountry.com/community/index.php?topic=24465.0

New project: 1968 Camaro with 6?.?0?  5.3 w/ Z06 cam/T56
http://transamcountry.com/community/index.php?topic=74591.0

ryeguy2006a

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Re: LS376/515 swap in a '78 Trans Am
« Reply #76 on: April 08, 2019, 11:52:31 AM »
Anymore progress?? We got my dad's Chevelle going this weekend and honestly has me looking at one for my Camaro. Curious to hear about yours.

1976 Trans Am LS1, 6 speed, C5 12.8" Brakes, LS1 rear 12" brakes, 17" Aluminum Rims, and much more...SOLD
My Build: http://transamcountry.com/community/index.php?topic=24465.0

New project: 1968 Camaro with 6?.?0?  5.3 w/ Z06 cam/T56
http://transamcountry.com/community/index.php?topic=74591.0

skisix38off

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Re: LS376/515 swap in a '78 Trans Am
« Reply #77 on: April 09, 2019, 07:26:04 AM »
Anymore progress?? We got my dad's Chevelle going this weekend and honestly has me looking at one for my Camaro. Curious to hear about yours.

Not much time to put into lately.  The progress I've made is that I've gotten the heater control working again and the stereo the dash back on.  Next is to finish the interior.  Then, the brake booster and flush/bleed of the that and the clutch.  At that point I'l start to drive it around some without a hood - I still need to get the shaker to fit to the new position of the TB.

ryeguy2006a

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Re: LS376/515 swap in a '78 Trans Am
« Reply #78 on: April 23, 2019, 07:10:09 AM »
Tearing up the streets yet?

1976 Trans Am LS1, 6 speed, C5 12.8" Brakes, LS1 rear 12" brakes, 17" Aluminum Rims, and much more...SOLD
My Build: http://transamcountry.com/community/index.php?topic=24465.0

New project: 1968 Camaro with 6?.?0?  5.3 w/ Z06 cam/T56
http://transamcountry.com/community/index.php?topic=74591.0

skisix38off

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Re: LS376/515 swap in a '78 Trans Am
« Reply #79 on: April 24, 2019, 06:42:10 AM »
Still dreaming of tearing up the streets!  I don't have it on the ground yet because I haven't gotten to spend any time on it, plus I just needed to walk away for a bit. 

I used a Gates lower radiator hose that is/was close to the LS conversion hose and I think it's twisted enough to limit the coolant to the engine, the fans came on like they are supposed to but the temps was still climbing and when it showed 225 I shut it down.  I have a different hose to try this weekend.  The remaining issue is the clutch is being a PITA to get bled, I had this issue last year too.   It all just takes time!!!  As we all know!

Re: LS376/515 swap in a '78 Trans Am
« Reply #79 on: April 24, 2019, 06:42:10 AM »
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