A distributor's performance is only as good as its drive gear. MSD Ignition has put a great deal of effort into researching and testing a variety of metallurgical compositions, heat treating and coatings to provide you with a durable, accurate and strong distributor gear. MSD engineers have built test fixtures and spent hundreds of hours testing and evaluating the metallurgy of our gears. The result is a special iron alloy gear that is treated to a low-friction coating process. To you this means long life, an easy break-in period and reliable performance! Features: Increased outer hardened layer thickness (RC 55-60)Micro polished surface for smooth contactProprietary formulated ductile ironMelonite QPQ coated reduces friction and initial wearInterstitial carbide concentration improves wear resistance and running propertiesPit Stop USA offers MSD Iron Distributor Gear - Ford 351W, .531" I.D. 85852 at low everyday prices. Be sure to check out all of our products from MSD including MSD Distributor Gears and MSD Iron Distributor Gears and MSD Magnetos Gears.