The 87 and older calipers are differant than the 88 and newer calipers. The 87 use a v groove kind of slide and the 88 use a pin type slider.

The 88 and 89 calipers are all the same v6 or 4 cyl. The 88 and newer calipers do use larger pistons.are larger in diameter.

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There are pics of both styles on the brake convesrion page.

Kevin