A-Body brake help

George Jets said
Here is the Disc/Drum manual master
You will have to research a little more. To see if it is the 15/16" bore. The bigger the bore, the harder the pedal is to press.

View attachment 1715724049

Have been going off the '73 Darts for the manual brake masters for the A bodies.

I almost positive I used that MC maybe for 1974 with my Kelsey Hayes front Disc /rear drum 10" but still seems I'm putting to much effort at the petal. If anyone does know the bore size off the 73 it would be helpful .