1994 Z71 5.7 TBI swap

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04-23-2009, 12:09 PM
94Z71

1994 Z71 5.7 TBI swap

I am looking for advice on my swap.
I'm in the early planning stages of a LS1 swap in my truck.
Can I use my existing transmission or should I upgade both ? (180,000 miles)
Should I be looking for a Corvette LS1 or a newer LS1 truck motor.
I have seen in a few posts the brackets work better on the vette setup, Is that the case with the truck LS1 ?
04-23-2009, 04:54 PM
92 6.0

First off welcome. Second I just got done putting an 05 6.0 in my 92 z71 and i used all truck acc. I would also advise putting in a new trans if your at all bit nervous about your current one. Its amazing the difference in power these new engines make. Also this thread is very very helpful. http://www.ls1truck.com/forums/lsx-t...onversion.html
04-23-2009, 10:55 PM
slo92chevy

You can use the existing trans you just need a different flexplate, but at least rebuild it cause thats alot of miles to have on a trans thats gonna have handle a stronger engine. Any LS engine is way better than the TBI crap, you can probably find the truck engines easier and cheaper than the vette. Good luck im just gettin started on my project, Cant wait to here it run.
04-24-2009, 07:45 AM
94Z71

thanks for the help..this site is going to be a great help.
04-24-2009, 07:50 AM
94Z71

i have the bed pulled, engine stripped and ready to pull. I'll pull the nose clip today to give me all the room I need.
What trans do you recommend..sounds like you have the same set-up. The existing trans and transfer case are showing wear and leak out the shaft seals so I'll need to change them as well.
04-24-2009, 08:26 AM
92 6.0

Trans and Transfer

If you want to keep it simple your best bet would to be Rebuild your trans and replace the seals in the transfer. I put a 4l80 in mine only because I got it for a heck of a deal and it came with a Transfer case. I believe its whatever you can afford and what you prefer.
04-24-2009, 09:05 AM
94Z71

thanks, sounds like a plan. I'll keep the post up as I progress or digress.
I've done engines but never a LS1 swap. should be fun.
04-26-2009, 12:47 AM
mcgojosh

i don't think you can run your tranny with a new pcm. i think you need to run a 95 and up 4l60 because the 94 and down have only a 12 pin connector but you need a 13 to make it work? someone correct me if im wrong? not 100 %
04-26-2009, 10:15 PM
slo92chevy

maybe he can use a manual trans wiring harness and pcm, or have some programming done to the pcm.
04-27-2009, 08:51 AM
94Z71

I'll find a 95 or newer engine/trans. I thought I could find a wrecked truck and pull the tank/pump as well.
03-14-2012, 11:17 PM
GMC1994

Quote:

Originally Posted by 92 6.0

First off welcome. Second I just got done putting an 05 6.0 in my 92 z71 and i used all truck acc. I would also advise putting in a new trans if your at all bit nervous about your current one. Its amazing the difference in power these new engines make. Also this thread is very very helpful. http://www.ls1truck.com/forums/lsx-t...onversion.html

Just came across this posting and I too am just starting my process.. 1994 GMC Sierra SLE Long Bed, 3/4 ton, 4X4, 4L80E(just had rebuilt so plan on keeping this a while), 5.7 TBI are the existing parts. Looking to swap a 5.3 or a 6.0 into the truck. So what you are saying is that I should be good to go with the 4L80E trans. But would this trans hold up to the new 6.0 LS?
03-15-2012, 01:07 AM
myzterray

Quote:

Originally Posted by GMC1994

Just came across this posting and I too am just starting my process.. 1994 GMC Sierra SLE Long Bed, 3/4 ton, 4X4, 4L80E(just had rebuilt so plan on keeping this a while), 5.7 TBI are the existing parts. Looking to swap a 5.3 or a 6.0 into the truck. So what you are saying is that I should be good to go with the 4L80E trans. But would this trans hold up to the new 6.0 LS?

4l80e trans is prpbably one of the strongest trans u can get. def handle a 6.0 with ease. ive seen some guys running 800hp set ups with a 4l80 with no problem
03-16-2012, 05:46 PM
HPICamaroSS

Quote:

Originally Posted by mcgojosh

i don't think you can run your tranny with a new pcm. i think you need to run a 95 and up 4l60 because the 94 and down have only a 12 pin connector but you need a 13 to make it work? someone correct me if im wrong? not 100 %

That correct...Atleast from what i heard. I went with a 4l80e in my 94 z71
03-18-2012, 10:42 PM
GMC1994

Quote:

Originally Posted by myzterray

4l80e trans is prpbably one of the strongest trans u can get. def handle a 6.0 with ease. ive seen some guys running 800hp set ups with a 4l80 with no problem

thanks for the info. with this tranny just being rebuilt about 3 hundred miles ago there is no reason to abandon this truck, just starting to learn the ins and outs. Also, easy enough year to work on without all the computer stuff. even with putting the ls swap in (5.3 or 6.0) looking for better gas mileage...... daily driver, about 75 miles a day.....and really like the truck...oh yea this forum is the best.....great advice!!
s
03-18-2012, 10:56 PM
myzterray

Quote:

Originally Posted by GMC1994

thanks for the info. with this tranny just being rebuilt about 3 hundred miles ago there is no reason to abandon this truck, just starting to learn the ins and outs. Also, easy enough year to work on without all the computer stuff. even with putting the ls swap in (5.3 or 6.0) looking for better gas mileage...... daily driver, about 75 miles a day.....and really like the truck...oh yea this forum is the best.....great advice!!
s

Yea no problem. Thats the reason I did my swap. I was getting horrible mileage. Good luck with the swap. Any questions feel free to ask.
03-19-2012, 06:37 AM
GMC1994

Quote:

Originally Posted by myzterray

Yea no problem. Thats the reason I did my swap. I was getting horrible mileage. Good luck with the swap. Any questions feel free to ask.

Quote:

Originally Posted by myzterray

Yea no problem. Thats the reason I did my swap. I was getting horrible mileage. Good luck with the swap. Any questions feel free to ask.

Appreciate the offer to ask questions. I recently have received a quote from a local guy here to do the swap for me for just under $6000.. So this sets me back, but think I can do this myself. have rebuilt a couple of engines, so i know my way around an engine compartment. the wiring part is the area i am a little nervous about. all of the safety lockouts and the fuel management..... i do know i can buy a harness for about 300 that is a good swap part so unplug the old and plug in the new. a lack of knowledge in these areas is what is holding me up.....