I have a 2004 ram 4.7l with a/t. needs a new engine, found a good deal on a used one from a 2002 cherokee 4.7 will it work? or would it be more trouble than its worth?

 

I don't think it will work for you. It is going to have 16T crank and cam tone wheels and yours has 32T. You'd basically have to tear it apart and swap those over....probably not worth it.
Edit: Not completely sure on the 16T thing for a 2002 cherokee so you'll have to look into that. I'd say if it has a JTEC PCM (3 plugs) then it's probably not going to work.