This is a complete rework that makes this swap much easier.
http://www.currentperformance.com/sh...-modification/
here is what I bought that helped me with my modified harness
http://www.currentperformance.com/sh...erelay-module/
hope this helps with the wiring decision.
As far as your exhaust manifolds, I used trailblazer SS manifolds and only had to trim a very minor piece from the right side of the frame. You should be able to see it on page 3/4 of my One Owner Short Step build thread.