More disc brake questions

Stock bore manual disc brake master cylinder for A body is 1-1/32" so this is why i am interested in the dippy master. Its the same bore as stock A body. This takes some guess work out of my equation. Caliper pistons being slightly larger than stock A body, it should soften the pedal , and make the calipers grip tighter. Sounds like a win to me.

Isnt the 15/16" master supposed to be for A body power disc brake cars? Trying not to get confused now.

Yes, 15/16" was used on the stock power brake A-bodies. But they were backward from the other body styles, E-bodies for example used 15/16" for manual and 1-1/32" for power, exactly opposite from the A's. Has to do with the pedal ratio change going to the power booster, the linkage was different for A's than the other body styles.