MoparPartsGiant.com offers the wholesale prices for genuine 2013 Ram 2500 parts. Parts like Rear Bumper 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, 8 Cyl 5.7L. Transmission: 6-Speed Automatic Transmission, 6-Speed Manual Transmission.