This universal GM style master cylinder is used on our power brake kits. Includes 3/8" ports on each side for ease of hooking up lines. This master cylinder has a 1" bore and is designed for disc/drum setups only. This master cylinder includes an adapter and can be used for power brakes or manual brakes. If you are running disc brakes we recommend using a proportioning valve. We also recommend using our brake light switch conversion kit when using this master cylinder, this kit moves the switch under the dash. Specs: 3-3/8" center mounting hose, dual, 1" bore, 3/8"-24 ports, Length 8".