The Good news you have a bad ass Jeep. The bad news you have a 2000.
How it sounds after Dodge bought Jeep and decided year 2000 would be the end of the XJ, 1999 and 2000 they made a shit ton of the Cherokee.
They also changed foundries on who cast the block. You'll notice the block stamp 0331 on the last run. They supposedly are known for cracking.
That said- theirs a 2000 4x4 Cherokee sport (black) with that same 4.0 parked outside my window right now - knock on wood it runs great and is not abused.
I think it's like any used car, if was treated decent it'll last a long time. If ya run the piss out of anything you'll have problems.
Here's a link specifically to the Jeep conversation-
http://www.jeepsunlimited.com/forums/showthread.php?391831-Cracked-0331-cylinder-head-castingsThis post was edited by said_aouita on Jul 23 2014 01:31pm