Feature●1955-57 Chevy Car Disc/Disc Brake Booster Master Cylinder Combo●Kits contain a 1" bore master cylinder with 1/2"-20 and 9/16"-18 outlets, 8" dual diaphragm booster, and a knob style proportioning/metering valve.?●Also includes the necessary hardware to mount the booster to your original 55-57 Chevy brake pedal.●Measures 14-1/4" from firewall bracket to end of master cylinder●Includes two 1/8" male NPT x 3/8"-24 IFF fittings, 23" vacuum hose, dual-diaphragm booster, pedal rod, and adjustable prop valve. M.C. has outlets on both sides (front 1/2"-20, rear 9/16"-18).Description