Looking for a firm brake pedal

Rockauto gives the bore diameters of most of the MC's they list. The first thing I would look for in "lost motion" is whether the shoes are adjusted correctly. If you assembled the self-adjusters correctly, and they work, you can back up and stop hard many times to make them adjust. That is the first thing I do after a drum brake job and it has always greatly lessened the pedal travel. I always install with the shoes not touching, since I don't want to risk dragging brakes.