1970 Blazer Brake Question

[Chad22873]

Well its been several years but I am back. I started my frame off in 2016 and got about 80% complete and then quit for a few years. Got back to it last fall and am now about 95% done. The only real problem I have now is brakes. I dont have any. Everything in the brake system is brand new. Here is what I have done so far...Bench bled the master, then vacuum bled the system at each wheel about 5 times. Pedal still goes to the floor. Power bled the system twice. Pedal still goes to the floor. Replaced the new master cylinder with another new one. Of course, bench bled it first. Then power bled the system, 4 times and pedal still goes to the floor. I get no air at any of the wheels. My rear brake pads are adjusted correctly. When I push the pedal, all 4 wheels do engage but not tight enough to have brakes and pedal still goes to the floor. I have done this my whole life and I just cant seem to figure it out. I thought maybe you guys might have some ideas. Its a simple system but I cant make it work.