GMPartsGiant.com offers the wholesale prices for genuine 2012 Chevrolet Express 3500 parts. Parts like Fuel Injector Rail are shipped directly from authorized GM dealers and backed by the manufacturer's warranty. Parts fit for the following vehicle options. Engine: 8 Cyl 4.8L Flex, 8 Cyl 6.0L, 8 Cyl 6.0L Flex, 8 Cyl 6.6L Diesel. Model Code: 1 TON CARGO EXPRESS, 1 TON COMMERCIAL/RV CUTAWAY, 1 TON PASSENGER.