These are the brake caliper tabs we use when building a Camburg rear end. These are designed for Wilwood’s 3.5? lug spacing. They also work with radial mount calipers with the proper machined adapters. These are CNC laser cut from thick 3/8? steel and are setup to be through bolted with a 7/16? bolt. These can be MIG or TIG welded. Select your axle housing tube size and the brake rotor diameter.