Kinda hard to tell without photos or a description of the calipers. Sidepull? Centerpull? Cantliver? V-brakes? U-brakes? Is it a road bike, touring bike or ATB? Dia-Compe made every type of caliper available on the market in '87, so if the calipers are original they could be anything that was available in '87. And maybe they're not even original. Pix, brake model name/number and bike model name/number should get you some helpful suggestions.