The trans harness is the same for the two or is it sidferenYes, that should work. You can swap over all of the wiring also. The Yukons ECM can be retunned for the 4l80E, but ether way you should be good. Just FYI, there is a forum just for 1988-1998 body style GM trucks. It is,
That forum is the number one forum for these trucks. Lots of knowledge there.
honestly not much reply over there of answers.