I am currently piecing together a TPI set up to go on my 88 ss monte and I just bought a ecm on ebay. The chip in the ecm has Delco AUJM 0580 on it. Doing a search here tells me that it is for a 89 5.7 auto transmission with 3.27 gears. My car will have the stock rear with 3.73 gears, will the prom need to be changed for the rear I have and what years wiring harness will work and does it have to be for a 305 or 350? Can a v6 harness be used, if so which would be best? I have the intake set up from a 86 trans am, 5.0 and 083 heads that I am going to use. I guess what I am asking is with the intake and ecm etc., which harness and years will work? Thanks for any help.