Had a '69 Satellite Drum Drum Car. Master cylinder was the 1 1/16th, swapped it out for the 15/16" bore master.
Huge improvement, the larger bore master the brakes would grab quick and the pedal was hard to push.
Swapped over to the 15/16" bore master, now I had a lot more control over when the brakes would come on, I could easily feather them without them grabbing hard.
Then the nice part it was much easier to push the pedal, much more of a pleasure to drive. Just felt way safer too, felt like I was in much more control of the car.
