I have a 92 laredo and I was wondering if it has a better rear end than my 98 xj??

All depends post photos of your axles specifically picture of the pumpkin. You can also look them up by the VIN online or call Dealership. That though is only going to tell you what it may have come factory. Best thing is post photos and we can tell you which one is better.

It depends on what rear end it is. The 92 will either have a Dana 35 or a 27 spline Chrysler 8.25. Your 98 will have a Dana 35 or 29 spline Chrysler 8.25. The only way the 92 would be better is if it has the 8.25 and your 98 has the Dana 35.