Brake pedal very hard on C10 1971

[syncrov69]

I rolled my c10 1971 for the first time today since 2007. I finished installing the brakes today. The brakes work but the pedal is really hard and I have to push the pedal with my 2 foots to brake. Lines, calipers, wheel cylinders and master cylinder are new. The booster been check and should be functional, one piece that I have not been able to verify is the proportioning valve. I also installed a proportioning valve and master cylinder for a C30. What could my problem be related to pedal too hard? Thank's for your input and sorry for my bad english