I have a 1990 454 TBI motor I would like to swap into my 1994 4X4, my question is will the wiring harness from the '94 be similar to the one from the '90 donor motor. I know the O2 sniffer will be different, but will the ECU mate up? I have the ECU from the 1990 but am trying to avoid tearing out the wiring harness from the '94. Also what about the tranny? I will also be swapping in the 4L80E in place of the 4L60E, will the 4L60 wiring harness mate up? Thanks for the help-

rogerwood, if u have the donor vehicle that the engine came out of, why don't u pull the harness from the whole truck. this will cut down on the amount of Tylenol u will eventually consume during the transplant.