I've heard 2 theories on why they put the LP axles in the 00/01 Cherokees.
The popular one was Chrysler saving money on a model they knew they were discontinuing.
The other, more worrisome rumor was that the new for '00, 2 piece cast exhaust manifold/dual pre-cat setup wouldn't clear the HP axle. When you do your swap, you might want to flex the axle all the way up on the drivers side before you put the springs back on, and make sure the new housing clears everything when it's sitting on the bump stops. You might have to extend a bump stop. Other then that, go for it,...