So Autozone (and possibly others, but I bought mine at Autozone) sells a 1'' bore "heavy duty" master cylinder for our cars, versus the 15/16 they originally came with:
https://www.autozone.com/brakes-and-tra ... 2558_89618
I believe Brian (Mottman) mentioned it to me in a brake thread I had posted, but I cannot locate where he talked about it.
However, I installed it on my Special, which in my opinion has had poor braking performance since I purchased the car in 2013 with 86k, and it seems to have helped.
One thing that you need to make sure you do is adjust the pedal travel on the master - that will control brake feel to some degree.