no brake pedal pressure.

[70-Chevy]

Alright,
I recently replaced every bit of brake hardware I could buy/find. I replaced drums, lines, wheel cylinders, pads, hardware, m/c, etc. I had really good brakes for quite a while until my headers burnt a pinhole in one of my lines after the clip broke from the chassis that holds it. Well, I replaced that line, and hooked it all back up. I bought a brand new m/c and bench bled it and bled all four wheels in the correct order with a one-man hand held vacuum pump. i got good, clean, solid, and clear fluid throughout all four wheel cylinders and I have absolutley no brake pedal at all. The pedal goes to the floor. Is there any ideas you gentleman have for me?

Also, can a proportioning vavle go bad and if it can, what could be some signs?

Thank you for all the help in advance gentleman.

Chris