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

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!
Thanks !!