3rd gen IROC/GTA steering boxes are an upgrade for most 2nd gens. Also, if you do the B-body spindle upgrade you will want to run 1LE rotors from a 3rd gen, but I think most just buy those new. Some folks like the basketweave wheels from GTA's (optional on other Firebirds), but I think you have to run 4 fronts or something like that. Those are 16" wheels so tire choices are getting limited. Otherwise not much, although I would like to hear more about the whole roller/door detent thing.