you're talking about a 4runner right? there were no real differences between the 88 and 89 runners. in 89 the pickups changed to the new design, but they didn't get the 4runner switched over yet. from what i remember reading, the 89 4runner was exactly the same as the 88, and they only made it for about a half year or so until they had all the tooling done for the 90 4runner. then they started making the 90 early.
so long story short, any 88 parts should fit your 89. anything from 86-89 should fit and most things from 84-85 should fit.