These 11.5" extra-long square U-bolts are designed for 2007–2021 Chevy Silverado 1500 and GMC Sierra 1500 rear leaf spring suspension setups where additional length is needed for 1"–4" lift blocks or thicker spring packs. Specs: 9/16" thread diameter and pitch, approximately 11.5" length measured from the bottom of the bend to the end of the threads, and about 2.5" inside width. Manufactured from high-strength steel and zinc plated for improved corrosion resistance, these extended U-bolts are built to provide strong, consistent clamping force to help secure the axle tube, leaf springs, and lift blocks in place with proper thread engagement on lifted configurations. Kit includes 4 U-bolts, 8 thicker washers, and 8 tall lock nuts for a complete install. Installation is straightforward with basic tools, and after installation fasteners should be torqued to the vehicle or suspension manufacturer’s specification and rechecked after initial driving.