Then somebody needs to tell that to Ford Motor Company. Every older Ford I've ever put a master cylinder on that had power brakes had an adjustable pushrod between the master cylinder and booster, including the 75 F250 I have right now. I even had to readjust it shorter when I replaced the master cylinder, because the new master cylinder was a little different and held the front brakes slightly applied. When I shortened the pushrod a couple of threads, all was well.
