64-73 Mustang Black Anodized Manual Brake Master Cylinder. Part #260-8555-BK. Master cylinder has a 1" bore and is a direct bolt on for 64-73 Mustang with manual brakes. This master cylinder is designed to be used with a manual brake set but can be used with brake booster as well if you should choose upgrade in the future. Master cylinder works with both disk/drum or disk/disk applications just change proportioning valve to match your set up. We also offer proportioning valves, boosters, brackets and brake lines.