so my car is a 1970 buick skylark. it had 4 wheel manual drum brakes. I recently put front discs in the car, but left the perportioning vaulve and the master cylinder the same with no power booster. I was wondering about putting a power booser on the car but do i have to change master cylanders and should i chand perportioning vaulves?
you need to change the prop valve regardless. with a power booster you would need to change the master also and use the other hole on the brake pedal arm.
