I've owned a couple of Cherokee 4.0's with 5 speeds bought used.The one we own now is a 96.Around here,about half the Cherokees are 5 spds it seems.The 96 is pretty snotty when ya rev it up,specially only pushing 3000 lbs of cheap Jeep,The engine is rated at around 190 HP,but doesn't feel stronger than my S10 4.3 5 spd with 160 or so HP..
I agree with Four on de Floor,why bother with non GM stuff in a GM,any Chevy part for a 250 6 is cheaper than AMC/Chrysler stuff.Since the engine is in an old truck,you can build reasonable power with a Chevy 250-292 without emission concerns.
The multiport Jeep injection sounds good,but it's a speed density system which doesn't lend it's self to modification easily(expensive)