CARFAX One-Owner. Clean CARFAX. Summit White 2017 GMC Sierra 2500HD Denali 4WD Allison 1000 6-Speed Automatic Duramax 6.6L V8 Turbodiesel Recent Arrival! Awards: * 2017 KBB.com Brand Image Awards Price includes some factory & dealer rebates, incentives, and discounts. Some buyer's may qualify for additional rebates, incentives, and discounts. Some rebates and incentives require financing through Hyundai Motor Finance, with approved credit. Not all buyer's will qualify for all available rebates, incentives, and discounts. Please see dealer for more details.