Vortec 5.3L V8 SFI, 4-Speed Automatic with Overdrive, and 4WD. Truck buying made easy! STOP! Read this! How tempting is this good-looking 2008 GMC Sierra 1500? The Sierra 1500 scored the top rating in the IIHS frontal offset test. Don't let the drumming of road noise wear you down. Bask in the quiet comfort of the cabin of this Sierra 1500 SLT. SON BUENA GENTE!!!