Anyone know what the difference is between the 82-87 arm rests and the 88-92 arm rests? Do they require different hardware/plastics to attach to the door? Thanks

 

You don't say which ones you are trying to install,so I will tell you what I know. The later style is more rounded and has no style line, the part that mounts up by your door handle is shorter than the older style and therefore requires a shorter screw. There also is no trim ring on the later style.
Hope this helps.

 

They will swap back and forth no problem. My 1992 arm rests were coming apart, and I replaced with the older ones.