I have read all the swap threads, including all of Pocket's excellent posts. I've also read all the posts on the LS1tech forum too, but I'm seeing a conflicting opinion between the LS1Tech folks and those on the board, and I think the reason is the way we're doing the swaps, but I wanted to verify this and put it into my FAQ on my build thread:

Which Engine harnesses will work appropriately based on Pocket's Harness rebuild? On the LS1Tech site they recommend not using the truck harness, and that may be the one I end up with since I'm building a 5.3 or 6.0 build. Does anyone have a listing of harnesses and maybe PCMs that can be used so I can add it to my FAQ?

 

Truck harness will work just fine. You got to de pin the whole thing anyways.

 

I thought it might... I think the main reason the LS1tech folks don't like it is that it has less pretty routing, but with the way that folks here have done the wiring, you can route it however you want.

 

FWIW I started with a 99 Grand Prix 3800 harness. I depinned it and started from scratch. Most GM harnesses have the same connectors.

 

'Tech people dont like them because they're harder to simply repin the body connectors and run as-is. Look at 90% of the swaps on there that didnt buy an aftermarket harness. They are stock out of the donor cor and into the swap including all the shortfalls and ugliness of how the factory ran them

My threads can use anything because you completely disassemble it and build it to suit your individual needs. FWIW, about 1/4 of the harnesses Ive built including the one in my 92 firebird were from a truck

 

That makes me so happy, I can't even tell you. I was going to pick up my motor first, but in retrospect, I've decided to do my interior and interior wiring, and pretty much everything else before I start the motor build.. I'd be pretty peeved if I got my motor running and couldn't drive it because there were no seats! Either way, This board is very , very blessed to have guys like you Pocket.

 

I found this on tech a while back. This is from a GTO, it might be an option to keep in mind due to the length of wire to the pcm, even though some rewiring would still be needed.

 

i followed the tutorials from pocket and lt1swap and used the free harness that came with my 5.3. if you've got the time, there's better things to spend your go-fast money on. i had to swap out the injector pigtails, but that was about it for necessary mods.