8" Dual Diaphragm Power Brake Booster Black This is the one that can be mounted under the floor or on the firewall - bolt pattern 3 3/8" center to center in a square pattern. 1955-75 Chevy all Models - Impala 1964-77 Buick Skylark, GS, 73-74 Apollo 1964-77 Chevelle, 70-72 Monte Carlo, 69-74 Nova 1964-77 Oldsmobile Cutlass, 73-74 Omega 1964-77 Pontiac, GTO, 69-72 Grand Prix, 1971-74 Pontiac Ventura.
