GMPartsGiant.com offers the wholesale prices for genuine 2011 Chevrolet Silverado 3500 HD 2WD parts. Parts like Emission Reduction Tank are shipped directly from authorized GM dealers and backed by the manufacturer's warranty. Parts fit for the following vehicle options. Engine: 8 Cyl 6.0L Flex, 8 Cyl 6.6L Diesel. Model Code: CREW CAB 1 TON, EXTENDED CAB 1 TON, EXTENDED CAB CHASSIS 1 TON 161.5, REGULAR CAB 1 TON, REGULAR CAB CHASSIS 1 TON 137.0, REGULAR CAB CHASSIS 1 TON 161.5.