Master Power Brakes and several other companies have small boosters and dual reservoir master cylinders designed to mount on the frame and connect to the original pedals for the 52 Chevy. You will need a proportional valve (so the car doesn't brake too hard front or back and send you in a spin) and an extra residual pressure valve if my memory serves me right because of the low mounting position of the master cylinder. Master Power can explain all this and guide you to a solution (check their web site). Pick up a copy of Street Rodder, you will find several vendors with master cyclinder/booster solutions. On the Innliners.org forum you can find a company called Buffalo Engineering who does a manual disk brake booster set up. The late 60s mustang or camaro manual disk brake master cylinder is popular. I believe the mustang has an integrated proportional valve. Good luck, the disk brakes are the best modificaiton you will make on your car.