looking for a new booster

I have a 67 Barracuda Formula S w/power discs (4 piston)..My booster was bad (broken spring or something so when you pressed the brakes, it just pulled the pedal to the floor so I put a different used one I had lying around and it doesn't work either (probably bad valve inside? there's no assistance to the brakes whatsoever with it). I cannot find a booster in my father's parts store system anywhere or local parts stores so I was wondering if one from a 73and up power disc car would work w/a proportioning valve?