350 in an xj

i recently bought a 94 cherokee xj in need a motor and a five speed trans. i was talking to my friend and he has a 350 just chillin so i want to put it into my xj. does anyone know how much of a pain in the ass that is. any help would be outstanding.

I know this is an older thread, but I have done some similar swaps before. Is this Jeep a 4x4? If it is the swap will be slightly more involved. I'm going to go through this assuming we are talking about a 4x4. You have the engine, now you need a transmission and a tranfer case. The easiest way to do this is to try and get all of your stuff from a donor vehicle. To really simplify things try to keep all of the stuff about the same year model. Where this swap gets complicated is deciding what parts you want to use. Do you want an all GM drivetrain, or would you just want to adapt the V8 to a Jeep transmission or transfer case? If I were doing the swap I would use the 350, a TH350 automatic transmission, and get all of the stuff to adapt this setup to an NP231 transfer case (which is found in all of the TJs, the Rubicon has a slightly modified variation). Try to stay away from the Jeep 5 speed transmission, it doesn't stand a very good chance of holding up behind a 350 even in stock form. If you keep this motor stock or close to it, you probably won't break anything.
With the right adapter kit you can kinda do what you want to as far as the swap goes. There are a lot of options as far as adapting the transmissions, transfer cases, etc. If you can get away with using adapters you probably won't have to modify your driveshafts.
Also, don't build your Jeep around your engine! Where people run into problems with these swap is being insistant on using what they have lying around. The motor is no problem, you just don't want to try to adapt some oddball transmission to the Jeep. When people start doing this they run into no aftermarket support, it can still be done, it's just a lot trickier and will empty your wallet a lot faster. As for the front axle if 4x4, get one of those manual cables to engage the front axle (instead of the vacuum solenoid) and really save yourself some headache trying to get it all to work once you've swapped the engine.