Maroon 2016 GMC Sierra 2500HD SLT 4WD Allison 1000 6-Speed Automatic Duramax 6.6L V8 Turbodiesel Steven's Means Savings, Allison 1000 6-Speed Automatic, 4WD, Leather. No dealer fees on this listing are included! Awards: * 2016 KBB.com Brand Image Awards Buyers must take... via LIUsedCars