New 7" zinc plated power brake booster, master cylinder & disc/drum proportioning valve combo. This top quality power brake booster is designed mount directly to your factory firewall. This Mustang 7-inch power booster kit works great as an upgrade from manual to power brakes for vehicles with automatic transmissions. Also included in this kits is a new factory style 1" bore master cylinder and proportioning valve equipped to work with front disc rear drum applications.