ok i have a 1993 suburban 2500 with a 350 and 4l80e. Just had the 80 built about 5 months ago and all runs good. i picked up a 2008 5.3 all aluminum with 243 heads engine wiring harness the other day.
i am getting the ecm today also. i am new to the swaps into older trucks but have been reading for weeks ..lol what i dont know how will i wire this into my older 4l80e, i did not know if the tcm would talk to my older tranny. or is there a way to wire it in and have my original computer control it?

thanks