69 front disc brakes

Okay so my next question would be, If 73 duster parts would work, would a master cylinder of the same car work ? I have disc front and drum rear non power brakes. i can put up a pic tomorrow of the existing master cylinder tomorrow to help in the identification. Sorry I'm a newb to the mopar stuff and getting parts for a car that has had stuff swapped out over the years can be challenging.
Also the car has the bigger bolt patters rear axle.
Luke