Easy way to tell year is 87's have 6 head studs and 88 and up have 7 studs. Also intake has 5 studs on 87' and 88 and up have 6 studs. 87's have a rectangle tube upper a arm and 88 and up have a round upper a arm.

Hey go to lt500r then touch or clik onto 87-90 engine changes read up caws small crank changes mite have been made better to be safe than sorry u cld also go to partszilla.com an see if the parts and # s ur lookin to fix or change match up if small changes were made the part#s won't match cuz u don't want to screw up ur new crank.😢Good luk gettin that beast Rollin again 🍩🍩🍩🍩🍩 hahaha happy trails . Ty Bo