Clean CARFAX. Onyx Black 2013 GMC Sierra 3500HD Denali 4WD Allison 1000 6-Speed Automatic Duramax 6.6L V8 Turbodiesel *Bluetooth*, Special Financing Available!, **Apple CarPlay**, **Backup Camera**, Allison 1000 6-Speed Automatic, 4WD, Cocoa/Light Cashmere Leather. Recent Arrival! Reviews: * If you require a vehicle that can transport over 10,000 pounds without breaking a sweat, the 2013 GMC Sierra HD deserves a spot on your short list. Furthermore, most prospective HD truck buyers who place a premium on luxury will find the Sierra HD Denali worth springing for. Source: KBB.com * Impressive hauling and towing capabilities strong diesel engine and brakes refined and quiet ride solid build quality responsive steering. Source: Edmunds