BST BSSP 12.5in Extended Square U-Bolts Kit for 2.5in Leaf Springs — 9/16in Hardware, Heavy-Duty Clamp

BST BSSP 12.5" extended square U-bolts kit provides heavy-duty clamping for 2.5" wide leaf springs on 1988–2019 Chevy Silverado and GMC Sierra 1500 trucks.

When you’re restoring, upgrading, or reassembling the rear suspension on a Chevy Silverado or GMC Sierra 1500, reliable U-bolts matter. This BST BSSP kit supplies four extended 12.5" square U-bolts sized for 2.5" wide leaf springs and 9/16" bolts, with all necessary mounting hardware. It’s built to replace worn fasteners after leaf spring changes, lift-block installs, or when adding aftermarket spring packs, giving you secure clamping and correct fitment across many model years.

Will these U-bolts fit my 1988–2019 Chevy or GMC 1500?

Yes — this kit is designed specifically for full-size Chevy Silverado and GMC Sierra 1500 (including C1500) trucks from 1988 through 2019 that use 2.5" wide leaf springs and 9/16" mounting bolts. Measure your spring width and bolt diameter to confirm compatibility before ordering.

• Designed for 2.5" wide leaf springs
• 9/16" bolt diameter match for factory mounting hardware
• 12.5" inside bend length, suitable for extended or lifted setups
• Fits left/right and front/rear suspension locations as required

How does the 12.5" length help with lift or block installations?

The extended 12.5" length gives extra clamping reach, which is useful when you add rear lift blocks or stack additional leafs. Longer U-bolts ensure the leaf spring, axle plate, and block are securely fastened without stress on threads or nuts.

• Extra length accommodates added spring stack height
• Prevents thread exposure issues when using lift blocks
• Helps maintain correct axle alignment after modifications
• Reduces need for custom or adjustable fasteners

What’s included in the BST BSSP U-bolt kit?

The package contains a complete set to replace all four U-bolts on one axle: four 12.5" square U-bolts sized for 2.5" leafs plus the matching mounting hardware. Everything you need for a standard reassembly is supplied so you can swap out fatigued or corroded fasteners quickly.

• Set of 4 square U-bolts (12.5" inside bend)
• Matching nuts and plates for secure installation
• Hardware sized for 9/16" bolt applications
• Packaging suited for one axle replacement

Are these U-bolts durable for regular towing and hauling?

These U-bolts are manufactured to provide robust clamping for leaf-spring assemblies used in everyday towing and hauling scenarios. While they are intended as heavy-duty replacements, routine inspections and correct torqueing during installation are advised to maintain safety.

• Square bend design resists rotation under load
• Hardware included to ensure proper torque and clamp force
• Works with factory and many aftermarket spring packs
• Recommended periodic checks after heavy use

Who is this for: This BST BSSP 12.5" extended U-bolt set is aimed at owners and technicians working on 1988–2019 Chevy Silverado and GMC Sierra 1500/C1500 trucks who need a reliable replacement or upgrade for 2.5" leaf spring systems. It’s ideal for DIY mechanics restoring older trucks, shops performing suspension repairs, or anyone installing lift blocks or extra leafs who wants correct-fit, ready-to-install hardware.