I hope someone can point me in the right direction?

Man have I been reading all the previous posts about swapping front drums to disks. This weekend I did this swap so here's my platform. I have a 72 dart swinger, I changed upper control arms from a 73 disk car along with the spindles. I got a rebuilt master cylinder from the Advanced and new calipers. I retained the original drum brake distribution block and did not put in a proportioning valve as of yet. Everything is hooked up with the bleeders on top of the calipers. I bled the brakes and fluid comes out of all of them but no air! The fluid is steady but not a large stream like I'm used to. The pedal goes to the floor. After pumping several (like 6) times you get some pressure but then to the floor again. I have bled over and over thinking trapped air but I sit here now admitting defeat. :salut: After reading previous posts I see a few peeps here have had bad master cylinders. I did not bench check the master cylinder first but since I pumped the crap out of them for so long this should have taken care of this anyway. So 2 Questions.
1. Should I assume a bad master cylinder and take it back or am I missing
something?
2. Do I have to install a proportioning valve and replace the original
distribution box? I would rather fix this problem and get the brakes
working then install the proportioning valve when I put my line loc on in a
few weeks while doing all the line bending etc.
Thanks for any and all advice you may have, trust me I am in need of some help on this as it may hold me up from starting the paint job this weekend if I can't move the car.
Adam