I've done quite a bit of wiring on trucks.
Re-wired my old 72 GMC with a Painless kit, then later installed a TPI 350 and hooked that up with a painless kit also (came with the engine)
On my 68 I'm currently working on, I used an EZ wiring harness for the main truck part. I took a stock '04 silverado wiring harness and modified it by removing all of the junk that I didn't need. I then used a LSx fuse panel from current performance to hook all of that up.
I also hooked up cruise control to my engine. It being a drive by wire engine it was fairly easy, but took some relays to make it work. Here's a write up I did:
http://67-72chevytrucks.com/vboard/s...ght=dbw+cruise