I have an 01 XJ with the 29 spline 8.25 rearend, its getting 33's in a few monthes, 4.88's and alloy shafts but im still concerned about how well the axle will hold up for me. I wouldnt say a beat the crap out of it but im not always easy on the gas either, and plus its locked as well. I want to be able to get a little air with it too without breaking stuff, im considering trussing the front end to handle that a little better and doing a HP swap. Just wondering whats people experience is as to how well the 8.25 should hold up for me though, i got a deal on a cherokee D44 for 200 bucks and im wondering if its going to be neccesary.

 

It should hold up OK to what you dish, as long as you do not bounce it too much. It is a pretty solid set up. The D44 is an upgrade, but not a big one compared to what you have. If you already have the upgraded shafts and locker for the 8.25, I would say run it, and keep the D44 around for a "spare" at home. If you have a line on better shafts and locker for the D44, I would probably swap it in now, so you have your best foot forward.
As it sits, the 8.25 with better shafts is probably about the same in strength as the stock D44 (if it is stock). If the D44 is open, we all know the difference there

Both axles will break with enough bouncing

 

This may help.

http://www.naxja.org/forum/showthread.php?t=101345

 

If your getting air Id truss the front for sure..... I would continue to run the 8.25 and buy the d44 for a spare. You can always sell it later if you dont use it and make money on it.