IH offered these packages for SM tractors and others. What will work in a SM will also work in a late M with disc brakes or a M if the SM disc brake clutch and brake pedals from several are used along with other related parts. updated 560 parts used a bigger bull pinion bearing, Update differential used cone carrier bearings, Different differential carrier housings for cone bearings. It and the bull pinion bearing retainer plate also was different and used a different size o ring on both than early 560 and SM through 450 tractors. Later they started using a tapered shim between diff carrier and rear housing to allow for deflection. Since disc brake parts bolt to diff carriers it's no problem for a M.
