Hi I did just this conversion started with a m600 dark 2000 fitted a 1997 900ss engine problems were 1/ single phase charging on SS sorted by just connecting to two of the where's on reg rec 2/ needed m900 exhaust headers as they are a different length 3/ needed oil cooler and hoses 4/ different neutral light switch wireing needs mod 5/ carbs are same size but different jet sizes use 900 dynajet kit 6/ need m900 inlet manifolds Engine bolts in no probs if you want any advise just ask done lots more mods aswell