Yeah, it sounds like that rear axle was swapped out. Those 99's came with a D35 did they not...? The 44 came factory later on...?
Not having the D35 is to your benefit..."JUNK" IMO...You're looking at a D44 now and better off even with a 4 banger.
Those gears will do you well on the trail. Yeah, you might falter on the highway getting to where you want to go, but not that far behind.
C'mon guys...In 4th gear with that 4 "popper" he should be running equal to a 6 cyl. with 3:54's.....5th gear should equal/better him out...Not all that bad but better off on the trail.....right ?
Jeeps with 4 cylinders are "trashed" because drivers have abuse the skinny pedal. I've made that statement already but have been with those that "feather" it with success of road.