hey all, I have recently undertook a swap on my 2000 silverado. I am swapping in a 2003 LQ9 from a cadillac ext. I have the engine sitting in my truck. Made a conversion from its drive by wire to drive by cable to simplify things. The harness that came with engine was spliced, so i had to get one from junkyard from a 2001 5.3l tahoe. Well harness wont work with the 6.0l computer because harness has red and blue connectors and engine computer had green and blue. So I aquired a new computer to fit harness and had it reprogrammed to everything. Engine will crank but wont start. Any thoughts on this issue? I feel like I am very close but just missing something.

Thanks