kragen or az? I would steer away from them though, My buddy who works at kragen says they always have issues particularily with overheating, he now recomends the new jeep motors which aren't much more do you want me to check with him? long or short block.
the 4.0 block does not take overbores well from what I hear. Seems the cyl walls are already pretty thin and creates steam pockets around the cyl which don't cool as well.
If it were me I would look for one out of 98 or so jeep with lower miles and use the renix computer and controls, I think you jeep is a non HO right?