More disc brake questions

Based on this information above, a stock A body caliper piston is 2.50" diameter, and a stock A body manual master cylinder is 1-1/32" diameter bore. This is factory setup.

Cordoba brake pistons are 2.75" diameter. So according to this above information from DrDiffs website, if i use an aluminum 1-1/32" bore master cylinder in a manual brake config, which is the same as stock A body manual disc, along with 1/4" larger than stock A body piston calipers off a cordoba it should yield a softer pedal, with a firmer clamping force.

i think stock A body single piston callipers are 2 5/8",a 1 1/32" master will probably be fine.
As stated,i have used 1" master with 2 3/4" callipers ('73-4 E body pin style) and loved the brakes ...everything was new.This was on a '70 Duster