I wonder how many people who are saying the 8.8 is not much of an upgrade over the 8.25 are actually running it? I guess it all depends, like other people have stated, on what type of wheeling you plan on doing with it. I previously had an 8.25 in my XJ and I am not sure if I would trust it with the wheeling I do now. I am running a D44 front and a Ford 8.8 rear, 37"s and a heavier rig with a hybrid cage. You can pick a 8.8 up from a JY off of an explorer for $150.00 . - so super cheap, you weld on some spring perches, weld the tubes and boom! beef! I am also running the Iron Rock gusset - just for some exrta strength. You can get the whole kit for $240.00 -
https://www.ironrockoffroad.com/product/xj-ford-88-axle-swap-kit-w-truss.html The rear axle drive shaft flange adapter piece is $30.00
of course if you are not wheeling hard, the 8.25 could be good enough, and as stated a direct bolt in BUT
The great thing about the 8.8 swap is
1. Strong axle that can handle 37's
2. Numerous swap kits make it easy to swap in
3. Explorer axles can be found SUPER CHEAP -and are everywhere!
4. 31 spline axles
5. Come with disk brakes
6. Same bolt pattern 5x4.5 and super close in width to stock
7. LOTS of locker and limited slip options
There are beefier options out there, but more custom work is needed and are more expensive if you don't already have one (ford 9") or Dana 60's. I have been very happy with my 8.8 swap. and it has been a relatively cheap upgrade. If I eventually end up grenading it, I'll upgrade to something else!