Master is 1 1/8" bore mainly for all wheel disc brake cars but works with other many models.

1967 1968 1969 F-body Camaro / Firebird

1968-74 X-Body Nova, Ventura, Apollo, Omega

1964-67 A-Body Chevelle, El- Camino, GTO, Lemans, 442, Cutlass, Skylark, GS

1968-72 A-Body Chevelle, Malibu, El Camino, GTO, Lemans, 442, Cutlass, Skylark, GS

1970-72 Monte Carlo, 1969-72 Pontiac Grand Prix, Tempest

Square master cylinder usually seen on 70 and up cars - but works just the same.

GM A Body Chevelle, Elcamino, GTO 442, Nova. Master is 1 1/8" bore for disc brake cars. All 1970 GM A-body disc brake cars came from the factory with this master. The master is square with the bleeders. This is for cars that want to do the disc brakes correct like the factory. The hold off valve is 7/16-24 purple fitting. The earlier 68-69 valve has the wrong fitting size. These are all factory correct parts.

A-body Chevelle, Malibu, El Camino, GTO, Tempest, Lemans, 442, Cutlass, Skylark, GS

Monte Carlo, Ventura, Pontiac Grand Prix, Nova

All parts are based off the factory originals and fit just like the factory originals.