The 2001 will have the 0331 head unless it has already cracked and been replaced. However, the chances of the head cracking aren't as great as Jeepforum makes them out to be. Make sure that the cooling system is kept up to par and the jeep doesn't overheat, and you should be golden.
Now, that being said...the 2001 Jeeps have some peculiarities that should be noted.
Coil rail instead of distributor
Low pinion D30 instead of high pinion
Very small chance of 0331 crack
Misfire on cylinder 3 code is thrown on heat soak due to faulty injector shielding (if not corrected)
I would suggest the 1998. And that's coming from someone who owns a 2001. The 98 will have the slightly stronger HP D30 and no 0331 casting. Simply put, they seem to be more durable and easier to work on.
Plus, don't know how you feel about someone else's junk, but I don't like Jeeps that come with lift kits. It's hit or miss on who installed it, what kit it is, how it's aging....I would much rather deal with my own stuff.
Life is life and fun is fun, but it's all so quiet when the goldfish die.
2001 XJ 4dr, 3'' lift, LP D30 & Ford 8.8 w/limited slip, 4.10's
Front OEM skid and rear gas tank skid, rock rails