Need Help With My Brakes!!!!

[1970ChevyC-10]

Hi guys, i got a problem ive been trying to solve for a couple months now. I have a 70 c10 that i put 71 spindles on. I bought new rotors and a cpp proportioning valve for disk/drum. The master cylinder is new. Now the problem im having is that i dont really have any brakes. M pedal is a little stiff but when i press down it goes to the floor. It does stop but barely. I dont know if i dont have enough vacuum for the booster or what, i have the vacuum line going to make intake which is a edelbrock rpm air-gap. Also i have a comp cams thumper cam which says its not suppose to affect the vacuum too much. If i could get some help that would be great!