Vortec 5.3L V8 SFI FlexFuel, 4-Speed Automatic with Overdrive, and 4WD. All the right ingredients! Come to the experts! This robust 2007 GMC Sierra 1500 offers a tough-truck look and has the teeth to go along with it's bark. The Sierra 1500 scored the top rating in the IIHS frontal offset test. Rugged styling that grabs attention, not just from your buddies, but often from members of the opposite sex!