[RC-Monster Mike]

The Slipperential drive cups are sized for 8mm balls on the bone end - pretty standard 1/8 size, so any bone with an 8mm ball end will fit the cup. Last I checked, the Savage shafts used larger balls(9mm and 11mm on the xl?) on their shafts, so not a direct fit. I don't own a Savage, so don't hold me to it. ;-)