The drive side of the crank is different on the 87 from the 90, having said that if you were to buy the gears for the 90 crank I'm pretty sure it would work. an 86 crank would work to. I have an 87 crank/bottom end that I would get rid of if he can't find something crank appears to be in good shape, it has a newer rod so I would assume it had been refurbished not that long ago.