brake pedal still seems to low feels like only the fornt discs are working

[aidenj454]

I'm new to your forum ,hoping you guys can give me some advise.my 70 el camino has front discs, they look stock but I'm not sure and drum rears, I replaced master cylinder calipers,rotors, drums shoes,wheel cyls, spring, adjusters and rear end brake lines. I have bleed the brakes multiple times with vaccum bleeder, power bleeder, and even tried speed bleeders. The pedal still seems low, while out for test run, it seems like I only have front brakes. The rears have bled fine ,fluid flow, even gravity flow What have I missed? Only thing I haven't done is to bleed them old school way with two people. Could it be as simple as that?