88, 88.5, 90......
And the 88.5 is an interesting creature! Some of the early one's have the small D-shaft and T-case flanges that the 88's had, and some had all of the large flanges like the 90's had. Then there are the odd ducks like mine, that had "C" all of the above...lol. Large flanges on the T-case and small flanges on the diffs. But who know's what the P.O. of mine done to it!
88.5 was also the year they started swapping over from two rear brake lines to a single line. And the dash vents are different than the 88's. Square VS round. This is probably the most noticeable change. And I do believe there was some difference in the rear seats as well, but don't quote me on that one. The early rear seats had a shorter back than the newer seats, but like I said, don't quote me on that!