Master Cylinder:78-80 El Camino, Cutlass + Disc/DrumBrand new master with the plastic reserviour.. one of the early times when a NON FULL CAST IRON master was used in big car production. This is for disc Front and drum rear. Bore size is 15 16" (24mm) Fits: BUICK CENTURY 1978 1980 BUICK REGAL 1978 1980 CHEVROLET EL CAMINO 1978 1980 CHEVROLET MALIBU 1978 1980 CHEVROLET MONTE CARLO 1978 1980 GMC CABALLERO 1978 1980 OLDSMOBILE CUTLASS 1977 1980 OLDSMOBILE CUTLASS CALAIS 1978 1980 OLDSMOBILE CUTLASS