Skyjacker 6" Rock-Ready on an 88 XJ?

Everywhere I have looked lists the rock ready kits for 89 - 01 models, even the Skyjacker catalog. What is the difference between the 84 - 88 and the 89 - 96 XJ's? I got a good deal on a used kit from a co-worker and would like to put it on my 1988 XJ Pioneer 4.0L Auto. Will this kit work for me? Any help would be greatly appreciated.

why not just call Skyjacker, or a dealer? They should know why they have designed their kit and listed it only for those years.

The crossmember mounting holes are different on the earlier XJ's. This means modifications will have to be made to mount up the sub-frame/crossmember to the unibody. I know there are also differences that will not allow the use of the 8" kit on the optional early disco front axle but I believe that all of the issues are associated with the axle cradle. This won't affect the 6" kit unless there is something else I'm unaware of.