Disc brake conversion is driving me crazy!

[HSRACER]

So I bought a disc brake conversion kit and installed the rotors while leaving the manual master cylinder on as I ran out of time the day I did the conversion.

Last week I finished adding the booster bracket, booster and the new master cylinder.

The power brakes are giving me fits. After I put discs on it and left the manual drum/drum master cylinder on it, the truck stopped great and straight but took a lot of pedal pressure.

Today I bled the new system a couple of times and there is absolutely no air in the system.

Now it stops ok but takes crazy amount of pedal pressure. Worse than when the booster wasn’t installed. Acts like the booster isn’t working at all. I have a ton of vacuum at the booster.

It still has the drum/drum proportioning valve on it. I had that on it when I did the disc conversion only and it stopped great. I don’t understand what could have gone wrong.

Any help is appreciated.