Brake pedal is really stiff

Did some work today on the brakes. I swapped all the drums and shoes from my 71 Duster on to the 67 Valiant and drove it around. The good news is that the brakes worked much better. What I mean is when you mashed on the pedal, the car really stopped. Before it would have to roll a little bit like it gradually wanted to stop. The bad news is the pedal still felt way too stiff. There was just no feel in the pedal like I normally get from my Duster. I inspected all the original shoes from the valiant and they're all newer shoes. Can't have more than 500 miles on them. They all looked great except the drivers left front shoe. The larger shoe had a spot up near the top almost like that's just about the only part of the shoe that touches the drum when stopping. I'm guessing that's the culprit for the brakes feeling weak, but there's still no solution for how stiff the pedal feels.

I'm wondering if a 71 Duster master cylinder would work? Are there any differences in 67 Valiant MC push rods vs. a 71 Dusters?