Yet Another Bleeding Problem...

I have a 71 Duster that I'm having trouble getting a firm pedal on. Most everything is new (calipers, wheel cylinders, master, hoses, distribution block) and with a pressure bleeder, I am able to get a steady stream of fluid at all wheels. I bled the master before hand, but the pedal is still spongy. I even went fitting by fitting and cracked them open to make sure no air pockets got stuck but to no avail. I think I've put a couple gallons of fluid through the system and I'm about ready to pull my hair out! Please help...