2007 - 2010 Chevrolet GMC Silverado Sierra 3500HD DRW Dually Rear Wheel 3.73 Ratio LS 8 Bolt Measurements Backing Plate To Backing Plate 60 3/4", Center Leaf To Center Leaf 49 1/2", Calibers Facing Front, Staggered Shock Absorbers, Yoke w/ Balancer OPT Code: GT4 G80