Developed through years of racing experience, Mallory Aluminum/Bronze Distributor Gears are recommended for steel billet mechanical roller tappet camshafts and slot hard faced steel billet mechanical flat tappet camshafts. Bronze distributor gears absorb the increased wear caused by specialized camshafts and magnetos, and are easily replaced before costly damage to the camshaft gear occurs. Precision machined in Mallory's factory from the highest quality aluminum silicon bronze alloy for maximum durability. Mallory Aluminum/Bronze Gears, as with any bronze distributor gear, must be checked frequently and replaced often.