Monte Carlo V6-262 4.3L VIN Z TBI (1985)
Brake Master Cylinder: Specifications
MASTER CYLINDER BORE DIAMETER; 15/16 INCH EXCEPT HYDRO-BOOST - 1-1/16 INCH; WITH POWER MASTER - 1-1/4 INCH; WITH
VACUUM BOOST & 4 WHEEL DISC BRAKE - 1 INCH
REAR WHEEL CYLINDER BORE DIAMETER; 3/4 INCH