Wilwood/Strange 4 Piston Calipers soft feeling pedal

What is the bore of the master cylinder? Maybe to small? I use a Motive pressure bleeder and I don't even bench bleed the M/C. I just did mine on my68 Barracuda with the Wilwood M/C, Wilwood four piston fronts. and 11" Drum rear brakes. Pedal is high and firm.