Who makes custom wiring harnesses

[81Regal]

I found a 2 wheel drive 4L80E and a 6.0L out of two different mid 2000's pickups and looking to put it in my 79 El camino. I have the computer avalible for the 6.0 but some of the wiring harness has been cut up, not sure what if any of the harness goes to the transfer case.
I would be sending the computer out to be reflashed but does anybody do a custom stand alone harness to make this swap work since I would keep it fuel injected.

 

[Ribbedroof]

I did my lt1 myself. It's not terribly hard, and this is a good reference source, unless you 'd rather spend $400+ to have someone else do it.

http://lt1swap.com/wiringharness.htm

Seems like the standalsone's I've seen run $700+ from painless and similar outfits.

 

[81Regal]

That's a lot of good info. I don't really want to spend the money if I can do it myself. Not 100% sure but I think the wiring that is cut goes to the alt.