First, I'd bleed the system again. Start with the master cylinder. Bleed it the same way you would a wheelend brake, except the 'bleeder' screws are the brake lines exiting the MS. Make sure to do both of them seperately.
If that doesn't help, and you say you've already adjusted your rear drums, you MAY have a master cylinder [MS] problem.
With the engine running, make a firm brake application. Hold the pedal there for a few minutes. Does the pedal drop at all? If so, there is either a hydraulic system leak somewhere or the MS is bad.
Another check is to make a hard brake application...really hard, and hold it. Does the 'brake' lite on the dash come on? If so, this indicates a pressure differential between the front & rear systems that is either caused by air in the system of a bad MS.
Let us know what you find.