MoparPartsGiant.com offers the wholesale prices for genuine 2012 Ram 3500 Pickup parts. Parts like A/C Compressor Mounting 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.