i got a 01 sierra that has a 5.3 that was dropped in it. i bought the project from a guy who had to deploy. i finished mounting the engine and tranny and now im down to the wiring harness. i have the old harness and the new harness that came with the engine. he gave me a computer that was tuned by nelson performance for the 5.3 but the connectors fit the old harness only. i dont know what to do from here and really need some help. i read that you can make your own and im pretty good at wiring so im all for this. HELP is much appreciated!!!!!!!!!!!!!!!!!!!!!!!!!!!