1967 Dart GT
I've owned a 67 GTS Dart since it was 1.5 years old and the original equipment proportioning valve didn't reduce the pressure to the rear brakes enough resulting in premature rear wheel lock up. Even a new one did the same thing. The solution was an adjustable proportioning valve. Later I also install better pads on the front discs with slotted rotors and then the car stopped like it should. Mine are still manual.