Which size drums on 69 Dart? And some other brake questions.

I was looking at the master cylinders. Apparently the 69 Dart had a master cylinder with a 1" bore.

I find the Dr. Diff aluminum master cylinderes appealing. But they only come with either the 15/16" or the 1 1/32" bore. How different would those be from the correct 1" bore?

To be honest, I don't know what the current master cylinder is. From images online it looks like a lot of them, including the Raybestos one that does have a 1" bore. I do remember when this master cylinder was put on there in 2011 being surprised how hard the brake pedal was and that the brakes in the car were never like that before.

The other alternative seems like one of the reproduction Bendix sytle master cylinders with a 1" bore. Or just another Raybestos type one. Not sure which way to go.