GMC 4-71 Detroit Diesel Blower Supercharger Rotor Assembly 5138557 NOS. This item is new old stock and has been stored in a parts service center so box may show signs of storage wear. This item is in the category “eBay Motors\Parts & Accessories\Car & Truck Parts & Accessories\Air & Fuel Delivery\Turbos, Superchargers & Intercoolers\Superchargers & […]