Going by race tech the 86 has a 46mm shock body and 85 model has 40mm and a different spring series so check diameter of shock spring the same or trial fit ,The 85 and 86 models were very similar,and should bolt in, the part numbers are different because of the bigger shock body, seeing the 86 has a bigger piston in it , it should work better when set up . The valving will be different , i would ride it first and see what it like then revalve it to your taste.If you decide to revalve it check seal head for slop as you can still buy these new from rt , should be good.