1964 Chevy Malibu Master Cylinder

You can bleed it. Bench bleed the master by getting brass plugs and screw them into the two ports, then pump the master until you cant move the piston any more. Attach the lines, Have an aide press and hold the pedal crack the lines and retighten, repeat this till all air is removed at the lines, Don't let the master run dry, bleed rear cylinders by opening the bleeders and wait until the fluid dripps out. Close bleeders. Make sure the rears are properly adjusted, then test the pedal hieght
Your only symtom that I can tell is not bench bleeding correctly, or there are more leaks.

Answer to PM: Could I have gotten a bad one? All air is out.
Pssibly, don't forget, there is only remanufacture stuff on the market, so if it sat on the shelf a while anything is likley. Do you see any tubulence when the pedal is released? If yes thats good if no, the comensating port is blocked, What kind of pressure at the inlet does it have?

Another PM answer:Yes there is turbulence. Good, then if you put your finger tightly on the outlet, does it have good pressure? If you will listen to me put a good brass plug into the hole(s), snug them up, and just pump that master if it is good, it will get to the point when all air is out, that the piston WILL NOT MOVE! If this does not happen, it's Junk!Yes there is turbulence.