This is the best deal you'll find on a quality setup like this. The booster mounts with a 4-bolt pattern. The 4 bolts are in a perfect square and are 3 3/8" apart (center to center). It can be mounted on the firewall or under the floor.
1955 1957 Chevy Tri 5 BLACK OUT 7" Power Brake Booster Bail Top Master Disc Disc
1955 1957 Chevy Tri 5 BLACK OUT 7" Power Brake Booster Milled Master Disc Drum
Dual Diaphragm 8" Power Brake Booster BLACK OUT Universal Hot Rod Universal GM
7" Street Hot Rod Power Brake Booster & Master Cylinder Black Out Custom Car NEW
2X 7" Universal Slim Fan Push Pull Electric Radiator Cooling 12V Mount Kit Black
99-04 Mustang [BLM] Rear Black Out Panel Matte Black Vinyl Set COMPLETE (4 pcs)