Master Cylinder for Four Wheel Disc Brakes, Ambidextrous Dual Circuit 20.6mm Big Bore, fits '49 '77 Bug, Ghia & Thing opt head temp sens thr opt for heads 25 Chromoly Rocker Arms on Type 4 25 Chromoly Rocker Arms on Solid Rocker Shafts ** Case and Heads will need to be opened to the appropriate Bore size & Case will need to be Stroker Clearanced for the larger crank Make Model Year Body Type Volkswagen Beetle 1949 1970 Convertible Volkswagen Beetle 1949 1977 Sedan Volkswagen Beetle 1949 1977 Sunroof Volkswagen Karmann Ghia 1957 1974 Convertible Volkswagen Karmann Ghia 1967 1974 Coupe Volkswagen Thing 1973 1974 Base 6mm master cylinder is the perfect solution