The engine types may include 4.3L 262Cu. V6 GAS OHV Natura lly Aspirated,4.8L 294Cu. V8 GAS OHV Naturally Aspirated,5.3L 5328CC 325Cu. V8 FLEX OHV Naturally Aspirated,5.3L 5328CC 32 5Cu. V8 FULL HYBRID EV-GAS (FHEV) OHV Naturally Aspirated,5.3L 5328CC 325Cu.