Replace your factory u-bolts with these zinc plated corrosion resistant Tuff Country 17858 Silverado/Sierra 3500/3500HD u-bolts. Designed specifically for lifted vehicles. This kit includes (4) u-bolts along with nuts and washers.Details: Rear Axle U-Bolt Kit Zinc plated to resist corrosion (4) U-bolts, nuts and washers Designed specifically for Lifted vehicles Made In The USA Sold As A Kit Fits: 2001-2010 Chevrolet Silverado 3500/3500HD 4WD (Lifted w/4 inch blocks) 2001-2010 GMC Sierra 3500/3500HD 4WD (Lifted w/4 inch blocks) Tech Specs: Bolt Diameter: 5/8 Inch Inside Diameter: 2.75 Inches Length: 16.5 Inches Bend Type: Square