8" Power Brake Booster Disc/Drum Valve Kit Fit for Chevrolet Bel Air Nomad 150 210 Series 1955-1957 99431061Features: 8" Dual Zinc brake booster with Bail Top Master Cylinder This 8" booster is ideal for most small to mid size street rods and customs. The booster mounts with a 4 bolt pattern. The 4 bolts are in a perfect square and are 3 3 8" apart (center to center). The master cylinder features a 1" bore and the ports measure 9 16" and 1 2". This master cylinder will work with any drum drum, disc drum, or disc disc setup. This kit is for the Disc Drum