Thank you for taking the time to look at this handsome 2017 GMC Sierra 2500HD. 2017 GMC Sierra 2500HD Denali 4WD Allison 1000 6-Speed Automatic Summit White Duramax 6.6L V8 Turbodiesel Allison 1000 6-Speed Automatic, 4WD, Cocoa/Dune w/Perforated L...