Find new and used GMC Sierra 1500s for sale on RacingJunk.com. The GMC Sierra 1500 may be a half-ton, but it’s a serious truck for serious truck people. It’s not all about Pro work trucks, though – models such as the Sierra SLT, Denali, and AT4 allow you to determine what should be expected from a high-end half-ton pickup. Even as a base 2WD work truck, the GMC Sierra is an elite performer in its class, but true connoisseurs may opt for a 4x4 with the available Duramax turbo diesel engine.