MBM PBUC4954-K - Chevy Car 7" Dual Booster Master Cylinder Pedal Assembly Kit this is a Premium MBM made booster. And includes a few features others do not, like the Dual Diaphragm Booster that will give you up to 27% more braking pressure over the single diaphra. Application info: Mounts in the factory location No major modifications needed NOTE: A few things to look out for before purchasing. This is a list of things that will prevent this booster from fitting. 4 Door vehicles