Disc Brake upgrade not performing as expected

Hello all

I just did a CPP drop spindle, drum to disk conversion on my 58 Chevy Bel-Air. Everything is functioning but the pedal seems "stiff" (like manual brakes) at low or idle speed. Could it have something to do with the vacuum line and maybe how the engine idles? 383 Stroker engine with high perf cam, etc...etc..

Thoughts? Anyway to enhance or adjust? I still have drums in the back but thought this upgrade would significantly improve my braking and so far it has not. Thanks RayJ

Also at higher speeds the pedal seems more normal but sqwishy or low.

check your engine vacuum if below 18 inch of vacuum when driving then you may need a larger brake booster or a hydra boost cyd.