X2 on the OBDI 4.0l HO. It will boost your power considerably, is reliable and long lived and will cause you fewer headaches on the install.
It is also the ultimate deveopment of the 258ci, so it is more an ugrade than a swap.
However it has wiring to deal with, I suppose like all fuel injected engine swaps. It is also not a monster horsepower engine.
BagusJeep lives in Bali.
1981 CJ7 258ci - Bagusjeep
1984 CJ7 258ci - Puthijeep
1981 J20 258ci - Gladys
1951 Willys CJ3A/MB/M38 - Little Willy
1995 Cherokee 4.0 - CHEROKEE