For anyone that wants to try to do these themselves it's not so hard if you start with a "LS series" engine truck harness.
For the most part the engine harness is a standalone harness already. If you use the truck under hood fuse block you just have to hook up one power wire, one ground wire, and one ignition wire.
You would still have to get the computer changed for anything you aren't going to use from the original truck.
A great website for information on swapping in the “LS series” engine is
LS1tech.com.
Here is one specifically on harnesses:
Removing extra wires from a 99' LS1 harness.
On that website there is a section devoted to
Conversions & Hybrids. At the top of the section are several very good stickies. The most useful I think is
LSX Swap FAQ and Hall of Fame Threads I myself haven’t done any swaps but I have helped a few of my friends do them in their cars. I figure it’s good to get some practice in before I make the mistakes on my truck
Sorry for posting links to another forum, but right now that is THE source for “LS series” engine swaps.
