Standard brakes verses power brakes

[Ping]

I just purchased a 1971 Plymouth Valiant Scamp.  Someone had put power brakes on it.  They don't work well at all.  My question is:   When the brakes are changed to power or vice verca does the brake peddle have to be changed also.  Seems I remember someone taking power brakes off a 1966 Plymouth Fury and they had to change the foot peddle too......I am wondering if this could have anything to do with the brakes on my car.         Ping