Upgrade your car to an 8" dual diaphragm power booster and 1 in. dual bore disc brake master cylinder with our quick install kit. This upgrade kit allows you to upgrade your drum brake car to power disc brakes in no time. In this kit we include an 8" power brake booster, mounting brackets, adjustable proportioning valve and a 1 in. bore disc brake master cylinder. A great kit with a factory look and easy installation.