Allstar Performance metric weld-on caliper bracket for 3-inch axles — 1/4-inch steel, fits GM calipers & 11.75-inch rotors

The Allstar Performance ALL42102 is a heavy-duty, weld-on rear caliper bracket engineered to mount GM metric calipers on 3" diameter axle housings.

Built from 1/4" steel and finished in a natural bare-metal state, this bracket lets you attach 11.75" diameter rotors and OE-style GM metric calipers to custom or restored rear axle assemblies. Its weld-on construction provides a rigid, permanent mounting point designed for high-strength applications where precise caliper positioning and long-term durability are important. The bracket ships individually and is sized to match 3" outside diameter axle tubes common in many performance and restoration builds.

How does this bracket fit on a 3" axle tube?

The bracket is contoured to wrap and weld directly to axle housings that measure 3" outside diameter. Proper fit requires careful alignment and full-penetration tack welding around the tube to ensure a steady, load-bearing joint. After welding, grinding and paint or coating are recommended to protect bare steel from corrosion.

• Designed for 3" OD axle housings for a snug weld-on installation
• Full-contact flange shape to maximize weld area and strength
• Supplied as a single bracket; requires positioning and welding by a qualified fabricator

Will it work with my brake rotors and GM metric calipers?

This bracket is intended for use with rotors up to 11.75" in diameter and GM metric calipers, providing the correct offset and mounting pattern for those components. Verify rotor thickness and caliper piston location to ensure there’s adequate clearance and pad fitment. Minor adjustments during mock-up are common when combining aftermarket parts.

• Compatible with 11.75" diameter rotors as specified
• Matches GM metric caliper bolt patterns and mounting positions
• Check rotor width and hub geometry before final installation

What materials and dimensions should I expect?

The bracket is formed from 1/4" thick steel for a robust, durable mounting point and it is supplied in a natural, uncoated finish. Package dimensions reflect the shipped item size, and the bracket’s shape is optimized for strength where the caliper mounts and where it meets the axle tube. Finish preparation after welding will extend longevity.

• Constructed from 1/4" (0.25") thick steel for structural rigidity
• Natural bare-steel finish, ready for primer, paint, or coating
• Package dimensions: approximately 26.9 x 19.6 x 0.5 cm for shipping reference

How should I prepare and install the weld-on bracket safely?

Installation requires basic fabrication skills: fitting, tack-welding, checking alignment, finish-welding, and then protecting the finished welds. Use proper welding equipment and safety gear, and perform brake component mock-up with hub and rotor in place to confirm caliper centering. If you’re not experienced with axle welding, consider a professional welder or shop to ensure safe, reliable results.

• Tack-weld to verify caliper alignment before full welds
• Use full-penetration welds and grind smooth as needed
• Coat or paint welded areas to prevent corrosion

Who is this for: The Allstar Performance ALL42102 weld-on caliper bracket is aimed at builders, restorers, and race teams installing GM metric calipers on custom or rebuilt 3" axle housings. It suits anyone needing a strong, permanent caliper mount for 11.75" rotors—from hot-rods and street/strip projects to competition vehicles—provided installation is performed by someone familiar with axle welding and brake system setup.