I am swaping my good drivetrain (4.2 staight 6) from my 88 wrangler to a 4cy 91 wrangler fuel injection. I need to know if i just have to swap the computer of the jeeps or do i have to swap wiring harness and the computer. Also i was wondering if I could just buy motor mounts for my 6cy motor and the will bolt on & replace where old 4cyl mounts were?

Well right off the bat no. The 6cy mm's are in a different position on the frame. They have to sit farther up because of the longer engine. So you will have to change out the mounts completely.

Also I'm not completely sure, but I think you might have to retro-fit some things to go from FI to Carb. And do you have emissions testing where you live? If so then you won't be able to swap in an engine from an older year vehicle into a newer due to the differences in the emissions equipment.

Give Novak a call, they are great people, and can give you the low down on the swap.