GMPartsGiant.com offers the wholesale prices for genuine 2016 Chevrolet Express 3500 parts. Parts like Exhaust Attachment 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.