Modification to a 4 drum master cylinder for use on 4 wheel discsv. ?

Nothing, when I get finished with my Dart, I am anticipating 11.70s in street trim. I have plenty of power to get the car going but, Im thinking you cant have to much braking power.
Its a safety issue.
My 65 Valiant ran 11.40s in the same trim I drove it 12 miles one way to work everyday for about four years. KH disc brakes on the front and 10" drums on the rear. It stopped very well. I slowed down fine to get off on the first return road. I like the look of the engine. Looks like you've made some progress!