Hard brakes

OK, while I am waiting for my new cylinder head to arrive, I can work on other things.

So here is a brake question.

I have a 1966 Dart 270 Wagon.

It has manual brakes. Single chamber master cylinder.

The brake pedal only seems to travel a very short distance and it is also really hard. In other words I step on the brakes, the pedal moves a little, then I have to really lean in to it to get stop the car.

The brakes work well, but I do not remember having to use that much muscle to stop a car before. I have had plenty with manual brakes.

Any ideas what could cause that? Would changing the brakes to a dual master cylinder help the car stop easier?

Thank you!
Author: Shrug