Upgrade your power brake car to a 9 in. slimline power booster and a 1 in. dual bore master cylinder with our quick install hydraulic brake booster kit. This 1971-73 Mustang power booster kit allows you to upgrade your factory power brake car in no time. In this 1971-73 Mustang hydraulic brake booster kit you receive the brake lines necessary to route from the new master cylinder to your factory distribution block. Additionally we include an adjustable valve which will be installed to your rear brake line with the hardware supplied. This adjustable valve allows you to fine tune the amount of pressure your rear brakes receive in order to prevent rear wheel lockup. With this 1971-72 Mustang power booster kit you will also receive a pushrod adapter for your factory brake pedal. A great hydraulic brake booster kit with a factory look and easy installation!