Okay guys, got e few questions. My 14 year old son and i are starting the swap in his truck. This is what wer'e workin with.

05 4.8 from an express van that had 4l80e behind it.
Pcm and harness from said van above.

Going to be using my 4l60e from my 99 t/a

Planning on doing the harness myself, What's it going to take to wire the harness to control the 4l60, or would it be easier to start with a harness
from a truck that originally had a 4l60. Guys any help would be greatly appreciated. Any other problems you can think of i may run into, Please let me know. Thanks in advance.

 

Anyone?

 

Are you sure there was a 4L80E behind the 4.8? Seems a bit of an odd combo as I thought they were only behind 6.0's. I have been wrong before.

The difference is a few pins get swapped on the same plug and the PCM needs to be told it's running a 4L60E. If you have the PCM that came with the engine any tuner could tell you which engine you have, the VIN of the original vehicle and confirm the transmission - all by reading it.

By the way, the service numbers on the PCM itself won't tell you much that you didn't already know.

 

The 4l80e behind a 4.8 is a van thing, weird I know, but I've seen it before. As far as using the 4l60e, like was said, its only a few wires that are different and the 60 only uses one speed sensor, it's not that hard to rewire. Then tune the PCM for it and your done. Sounds like a fun father son project, good luck and have fun with it.

 

Thanks guys thats exactly what i wanted to hear. Any idea where i may find the info on
repining the connector and whats needed at the pcm?

 

Great swap!
I put a 4.8 and a 4L60E behind my 1969 C-10 and I couldn't be happier, I am so glad I went for the 4.8. The small engine economy allows me to drive it all over town with no regrets on my wallet... -Try $10 pesos MEX a liter when the minimum wage is at $55 pesos a day; remember this when you complain about high gas prices
Anyway I couldn't find the file for changing the position of a white wire at the transmission connector, but I remember I used a manual for a Painless harness to know which cable it was, maybe you can find that manual in their website.
Then simply ignore the front sensor Converter RPM IIRC, do a segment swap on the ECM's programming and you are ready to go.
I used HP Tuners for the programming and I did my own harness, saved a few bucks and also got a sense of pride of doing it myself.
I'll look for these files but I am sure you can readily find'em through a simple web search.
Keep the pictures coming.

 

Thanks Rat, I will check painless for that manuel. I'm finding alot of info on the 99-01 harness. Still hunting for the 05 Blue Green connector info. I will post pics as we go

 

Okay here's where what we are starting with.[IMG][/IMG][IMG][/IMG][IMG][/IMG][IMG][/IMG]

 

doin the same swap for my truck, but i'm also converting it to 4x4... i'll PM u the pins when they upload on photobucket

 

Greatly appreciated Joshua..

 

did the front clip come stock like that? cuz mine has single headlights and park lights below, and mine is an 85... oh and when u get to it, can u let me kno which pins are to the alternator?

 

It's a 90 model crewcab or blazer front clip. As far as the alternator it's all in the harness i believe all you need to do is run the heavy gauge wire from the back of alternator to the positive side of the battery. Someone please correct if i am wrong.

 

yea but i've already un pinned the harness to do away with the tranny...

 

Heres the 60e-80e and vice versa pin info. https://ls1tech.com/forums/conversio...ompatible.html

 

are you going to lower this truck?

 

Thanks, just what i needed.

 

I think he wants to do a small drop on it, nothin to extreme.

 

Try this should be what u need. Hope it helps
https://ls1tech.com/forums/7807777-post76.html

 

i used "lt1swap.com" for my pinout, he also does ecm tuning and reflashing. LOTS of good info on there as well for making fuse blocks, vss, modifying harness, tach wiring..etc etc..

 

Just an FYI, the Green/Blue PCM you are using is drive by cable. If you go 4L60E you should be able to use a 2004 GTO 4L60E tune as a baseline (Most Green/Blue PCMs were DBW). Another option is to convert to a red/blue PCM and put a silverado tune in it. No segment swaps necessary.

Jon
PSI