4.0 interchangability

Hey all, recently got a 99 cherokee and threw 4.5" on the suspension and some 31's along with all new steering parts and u joints. She has close to 200k on her and you can really feel the drop in power, especially at altitude. I have decided to replace the engine with a stroker and think I may have found one already built that may suit my needs. The problem I am having is that i dont know if it will fit my jeep. My jeep is a 1999 cherokee with the stock engine, but the block I am looking at origionally comes from a wrangler (tj), and I am not sure of the year (96-06). First of all, will the short block from a tj allow my covers, intake, distributor, pumps, etc. to bolt right on? and secondly, is there any change through the years that would cause me problems? I have searched all over looking for this info, but could not find anything definative.
Thanks in advance,
John

The short blocks are externally identical - save for the fact that the knock sensor boss on 1987-1990 went unmachined for 1991 and later (and I think disappeared altogether ca. 1997, but I'm not sure on that one.) The short block differences are:
- A gradual lightening of the casting (~40# or so for 1991, and another 10# or so for 1996/1997)
- Addition of a main bearing cap brace for 1996 and up (which can be retrofitted to earlier blocks.)

Your 1999XJ should still have the #0630 head, which can be readily checked by looking at your ignition setup. If you still have a dizzy and wires to the plugs, you have the #0630 - if you have a "coil rail" screwed to the head and no wires, you have the #0331 head. The XJ was slated as having the #0331 head and COP/DIS ignition for the 2000 model year, while the TJ and WJ got it for 1999MY - that's something you should check. I do believe, however, that the distributor can be retrofitted into the later engines (same block, IIRC) by taking out the oil pump drive that was dropped in place. The #0331 head is the only OEM head that has machined holes for the screws for the coil rail - but that may be unimportant (file under: Trivia.)

If you want to know if you have to deal with swapping out COP/DIS for your dizzy or not, just ask the guy selling the engine if it has the coil rail setup for the ignition or not. If it doesn't, then no worries.

The engine assembly should be identical, if the head numbers match. However, manifolds could be different (reuse your XJ stuff,) and some bolt-ons may be different (reuse your XJ stuff,) but the core of the issue isn't at issue here.

You should be able to use the long block with your intake setup and be done

Thanks for the info guys, great to know, and great to hear. I have been doing a little research on doing this stroker swap. I plan on putting in a larger exhaust; headers to tailpipe, intake, 27lb injectors to prevent knocking, and I assume something to alter the computer. What exactly is it I need to do to the computer? Is it another computer i need to piggyback the stock computer? or is it codes that a shop has to input into my stock computer?
thanks again
john