GMC Sierra II (GMT800) gallery (1999–2007)

The second-generation GMC Sierra was introduced in 1999 on General Motors' GMT800 architecture, bringing significant structural improvements with a three-piece modular hydroformed steel frame and four-wheel disc brakes. The truck was manufactured in three primary cab configurations: Regular Cab, Extended Cab with rear-hinged doors, and full four-door Crew Cab across light-duty 1500 and heavy-duty 2500HD and 3500HD payload classes. The engine lineup shifted to the modern Gen III Small-Block Vortec V8 family, including 4.8-liter, 5.3-liter, and 6.0-liter displacements alongside the base 4.3-liter V6, while heavy-duty models received the 8.1-liter Big Block V8 and the newly engineered 6.6-liter Duramax turbo-diesel V8 paired with an Allison heavy-duty automatic transmission. In 2001, GMC introduced the flagship luxury Sierra Denali trim, pioneering full-time all-wheel drive, upscale cabin appointments, and available Quadrasteer four-wheel steering. In 2004, a mild-hybrid Parallel Hybrid Truck (PHT) variant was introduced. A comprehensive facelift in 2003 brought restyled front-end fascias and upgraded electrical systems, maintaining production through 2007 alongside its successor under the Sierra Classic nameplate for North American and Middle Eastern markets.