There are some small differences in the interior and maybe exterior. But depending on what the XJ came with as it was ordered can change what it could be classified as. Like I had a 88' Limited and I have a 90' Pioneer and the only difference was the limited had power seats, mirrors and leather, but the pioneer has the skid protection. Here are some websites that you can read up on to get a better idea of what the years and models had to offer, but like I said, it depends on what extras were ordered...
Years and models breakdown
Trim lines & Packages
Cherokee history