Leaf Spring Axle Black Extended U Bolts (10 Inch Length, 2.75 Inch, Leveling Kit [FITMENT] Compatible with Chevy: 2001-2007 Silverado 1500 HD, 2001-2004 Silverado 2500, 2001-2010 Silverado 2500 HD, 2001-2007 Silverado 3500, 2007-2010 Silverado 3500 HD. Compatible with GMC: 2001-2007 Sierra 1500 HD, 2001-2004 Sierra 2500, 2001-2010 Sierra 2500 HD, 2001-2007 Sierra 3500, 2007-2010 Sierra 3500 HD. MUST have 8-Lug bolt pattern. Fits both four-wheel drive 4WD and two-wheel drive 2WD RWD models. May fit other vehicles. Verify length and width needed, as well as the bend shape. [SPECIFICATIONS] Includes (4) Square Bend U-Bolts, (8) Nuts, (8) Washers. All parts are Hardware Grade 10.9. Ubolt Length: 10.5 inches. Ubolt Inside Width: 2.75 inches. [PRODUCT BENEFITS] For use with 1 to 3 inch lift blocks / plates. These extended U Bolts ensure proper thread engagement when securing your lift pack and leaf springs to your vehicle. Designed to be solid so that it does not bend or warp under stress, and as long as they are properly installed should last the lifetime of your vehicle. [MATERIAL MANUFACTURING] The U-Bolts are made from Heat Treated Carbon Steel for optimal durability and fitment. All parts (including the Nuts and Washers) are hardware grade 10.9. Zinc plating / coating prevents surface corrosion and rust. [INSTALLATION] These square ubolts do not come with instructions but is completely bolt-on. Please consult a professional if you need support. Should take 1-2 hours to install. Make sure nuts are tightened evenly (refer to diagram for sequence) and that they are torqued to correct manufacturer specifications. The use of loctite is recommended to protect the threads from rust / corrosion and prevent loosening from vibrations.