Jeep engine swap 2000>1997 4.0

Engine controls are likely different... Make sure that you retain all old stuff and know where it hooks up. It's easier to change any different sensors etc before you install into vehicle. make sure that accessories on front of engine are the same, and that exhaust exit on pipe is located in the same place. Exhaust manifolds like to crack where pipes are joined together. make sure they are OK before using manifold. Base engine assembly is identical so there shouldn't be any major problems. If new engine has over 150k on it, you may want to change timing chain before using it. (its not mandatory, but you would be surpriseed how many engines, I've seen with fairly worn out chains at that mileage)
Good Luck