MoparPartsGiant.com offers the wholesale prices for genuine 2012 Ram 3500 Pickup parts. Parts like Park Brake Assembly, Rear Disc are shipped directly from authorized Mopar dealers and backed by the manufacturer's warranty. Parts fit for the following vehicle options. Engine: 6 Cyl 6.7L Diesel. Transmission: 6-Speed Automatic Transmission, 6-Speed Manual Transmission.