Late 80s early 90s have a D44, I got mine out of an '89. You can tell the diffrence by looking at the diff cover. There is a comparison somewhere on the web with pics of all the different axles, dunno where. I'm not sure if the 8.25 is better or not, but it probably doesn't have the same WMS to WMS length. XJs and Wranglers have a 60" length.
Joop