20. The CPP booster/master set up is preassembled as well, and is even plumbed with new brake lines and a proportioning/distribution block. The unit is ready to go, but we would recommend removing the brake pedal pin before installing so you are not fighting it. CPP also provides new nuts to hold the booster on the firewall. They include a fine and coarse thread set of nuts to cover all applications. We needed the coarse thread nuts for this '68.