GMPartsGiant.com offers the wholesale prices for genuine 2016 Chevrolet Impala New Model parts. Parts like Automatic Transmission Assembly are shipped directly from authorized GM dealers and backed by the manufacturer's warranty. Parts fit for the following vehicle options. Engine: 4 Cyl 2.5L, 6 Cyl 3.6L. Model Code: LS 4 DOOR NOTCHBACK, LT 4 DOOR NOTCHBACK, LTZ 4 DOOR NOTCHBACK.