MoparPartsGiant.com offers the wholesale prices for genuine 2020 Ram 2500 parts. Parts like Wiring - Chassis & Underbody 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, 8-Speed Automatic Transmission.