Vortec 4.8L V8 SFI and 4-Speed Automatic with Overdrive. Classy White! Isn't it time for a GMC?! GMC has outdone itself with this attractive 2004 GMC Sierra 1500. It just doesn't get any better at this price! It's the combination of advanced design and precision engineering that gives the Sierra 1500 the pinned-to-your-seat acceleration.