[69-z28]

I have a 1984 that I converted to a 350 throttle body. I used the complete engine, trans and the harnesses from a 1987. both trucks had dual tanks. I used all the 87 stuff. No matter what I do I cant get power to the fuel pumps. If I hot wire the pump it fires right up.Heres a few things I have done. New fuel pump relay. New oil pressure switch. New oil pressusure pod. Checked all fuses. New dual tank transfer modual . New right to left switch switch . new fuel sending units with pumps.Checked all fueses. I What am I missing .