Technical 8 or 9 inches.....brakes

Ok so I’m putting a universal power brake booster and master on the firewall. I think I have room for a 9inch booster if I want. So should I do an 8 or a 9?

 

Yes.

(for a more serious answer, tell us a lot more about the car and the rest of the brake system)

 

Oh sorry, it’s a big car. 1951 buick Roadmaster and it will have 4 wheel discs and has a small block Chevy in it

 

bigger the better!

 

Don't smaller boosters have two diaphragms to make up for a single large one? I think one would be better than two.

 

On a car that size you should use a 11" booster. If you only have room for 9" go dual diaphragm.

Chris