engine swap questions

my jeep: 1991 4.0 6cyl, 5-speed 4wd. 200k+ miles

i have a buddy who has an engine and tranny out of a 2000 or 2001 jeep cherokee. 4.0l 2wd tranny with 150k miles. since i really dont do much offroading i am considering swapping it into my jeep and not keeping 4wd. what would i need to do this swap?

if it's a 2001 engine you will have to modify it to fit into your jeep

the 4x4 -> 4x2 conversion is by far the easiest of your problems... i'd just pull the front driveshaft and be done with that. the harder part will be the wiring and extra cat(s).

If in Cal and a few other states. The law states that you would need to meet the BEST smoge numbers of the car OR engine used in the swap. SO from now on the engine is out of a 91 RIGHT. Else your going to need all the senors the ECU the 3 cat system etc etc from the NEWER 91 to be .
If the head is good off the 91 place it on the newer 91 engine. Also using the old intakes wood be simple and cheeper then making the newer stuff work on your XJ. With the old head the old poop pipes will work
Switch all sencers
Also the NEWER 91 head did crack but if it hasn't cracked by now it most likely will not.
The 91 head has a bigger poop port that many believe is better for making HP in the high RPM anyway.
luck