During my restoration i decided to convert my manual drum/drum brakes to a power disc/disc set up. I bought the kit from pirate jacks which pretty much included everything rotors, spindle, brackets, hoses, master cylinder and booster, etc. The issue im seeing is that the booster may be too big. Its almost right on top of the valve cover. If the cover ever had to be removed the booster would be right on the way. Its an 11 inch booster and i know they make smaller ones but i just want to make sure i get one that will work with my engine because i know there has to be a certain amount of vacuum for it to function properly. 400 Pontiac with 6x heads, 268 xe competion cam, 350 auto trans. Anyone been down this road before please share some knowledge.