I have a question I have a 2002 Discovery with 75K miles with a rusted frame and several issues except the truck runs great. I picked up a 2004 Discovery with a bad oil pump, turns out there is more wrong with it than the oil pump basically needs a new engine. My question is it possible to put the 4.0l motor in the 2004 and still use the existing computer in the 2004. The 4.0 does not have secondary air. If its not possible If I move the computer from the 2002 what else do I need to move with it the security module?