Sorry if I keep changing the story on you.  It's been 8 years since I have driven or worked on this car.  My memory is a bit fuzzy as I have changed it around more than twice.

Here is what I DO remember (and what I saw today). I remember that it is 1" bore, from a disc/drum application, somewhere in the late 70s or early 80s.  It has ports on the engine side, and is definitely aluminum. 

I think I am going to heed the advice given earlier and do a pressure check after I bleed them once more (eight years... might as well make sure).

The master cylinder is a disc/drum master cylinder.  I took the time to research as I wanted an aluminum one.  I don't remember the exact application, but it was a manual disc/drum application.

The adjustable prop valve has replaced the stock one.  Can I post a link?  Didn't want to break any rules in my first few posts.

So I have a 1970 Mustang.  It came with drum/drum non-power brakes.  I upgraded the front to stock disc brakes with an appropriate master cylinder and prop valve.  I expected to be able to feel a difference... no, not really.  I've bled them over and over.  Still not feeling it.  The brakes don't lock up at all. 

So, before I go and yank it all off, I wanted to know if there is anything I should be looking for that could cause this issue?