Feets- measured the pedal ratio. 7.037 I also checked my 72 Charger that came with front discs. 7.22 pedal ratio. I'm assuming you are saying I need a longer brake pedal for additional leverage. The pedal ratios tell me the pedal in my 72 is 3/16" longer than my 68. How much longer of a pedal would be necessary? Another thing. The brake pedal in my 68 sits very high, my Mopar buddy said that is typical of a manual drum set up???.
If the pedal was lower, closer to the floor would that help since the angle of the brake pedal would be closer to 90ยบ to the master cylinder push rod?

TJP- I will check that this weekend when the temps are above freezing for a change. What type of gauge do you use for testing the master and calipers?

My Dad always told me, when setting goals " avoid disappointment, aim low".