MoparPartsGiant.com offers the wholesale prices for genuine 2017 Ram 4500 parts. Parts like Main Shaft Assembly 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 6.4L. Transmission: 6-Speed Automatic Transmission, 6-Speed Manual Transmission.