Brake issue and I am at a total loss.

I have been on this problem for over a year. Actually, it has really just taken a backseat to building my garage, but I started this nightmare over a year ago.

67 dart convertible, 273 automatic, manual drums all around. Nearly 100% stock.

I have had the car over 7 years. The brakes were never that great. I did a complete overhaul of the stock system. I did not want to change it from original. I really do not get on it much, and I am probably more careful than I need to be. So I know a lot of you will suggest that I should have upgraded, and at this point I will now agree. The reason? I cannot get a pedal when I move to bleeding the front brakes.

My main problem is that I should not have replaced the entire system all at once. I did the shoes, master cylinder, prop valve and even the lines. I just got back on the project, and I even installed a second master cylinder from NAPA. I wish I would have done one part at a time so I could troubleshoot each part; however, I exchanged my original master cylinder, and I am fairly sure the shoes or lines cannot be giving me a problem.

Now here is what happens when I bleed the brakes.
Right rear: pedal gets a little stiff
Left rear: getting better- almost 100%
Front right: starts to lose pedal
Left front: I lose the whole deal. No more pedal at all.

I repeated this process three times with this new master cylinder. And this is exactly what happened a year ago that led me to giving up and focusing on my garage and other car--a 69 Road Runner.

I do not know what I can add. I bench bled it correctly. We bled them in the correct order five or six times. We do not have a leak anywhere. I just do not know.

Any of you have any ideas?

I looked into pushrods length, but I do not see where it could be adjusted???

I even took off the plate that holds the pushrod in from the back. It resembles a gasket and is held on with two bolts. I thought maybe the pushrod was not traveling far enough back, so at that point I was willing to try anything.

I know I left something out???

At this point, I would be willing to do something I have not done in probably 20 years, and that is to let someone else work on my car. My other option is a brake upgrade if it is guaranteed to solve my problem.

Anyone not tired of reading yet? And have some advice?