The 4-cyl dd is talking about is the old one. I think it's the one used in 70's-early 80's GM cars. It would be carburated & a lot less HP than the EFI from the YJs & TJs. I don't know much about how they perform in the Jeeps, but they were decent engines in the cars & very easy to work on. The 4-speed with no OD is going to put a damper on fuel economy, but should be ok, also. If you're buying a pile to save on fuel, forget it. Might send Lilgrnjeep a PM. He knows more than the average bear does about 5s. Good luck.