97 XJ Engine Swap Choice

I notice so much out there, was wanting some professional opinions (been out of the game for a while)
I still have my 97 Cherokee 4.0l, 3 inch susp lift, running 31's. (arb bumper winch snorkel, rack etc..)


Right now I max out going around 75 mph on the interstate and really struggle in the mountains. Been reading a lot on ls1 engine swaps.


Is it possible to do a engine/transmission swap that would let me sustain 20mpg on the interstate/highway roughly, with having plenty of room to get it up to 90/100 mph. This is a project me and my dad had back in the early 2000's and I would like to put some more money in it and get it up to standards and ready to last another 20 years. Thanks so much!

forgot to add, it is currently a automatic

sorry posted this in the wrong place

b2Squared said:

Is it possible to do a engine/transmission swap that would let me sustain 20mpg on the interstate/highway

Click to expand...

Not a chance. Maybe a really small diesel...but a gas V8? Never!

More importantly you should probably figure out what is wrong with the engine you have. If you can't go above 75 or struggle in the mountains your engine is not running correctly. Could be as simple as a bad sensor somewhere.

3" lift, 31" tires in a vehicle with the aerodynamics of a brick make 20mpg a challenge. My Comanche used to get 24. Then I put 5" of lift, 32s, regeared from 3.07 to 4.11s, swapped to an automatic, and I get 16-17. What gearing do you have?