GM A-body brake problem

[gmiles]

Did the search; read alot. The short of it is my power brakes feel like manual brakes.
1964 Olds Cutlass had power drum/drum. Bought the front disc conversion from OPGI. CPP booster, master, combo prop/pressure valve, braided front lines, etc. Now it takes a lot of pressure to stop.
I have 20" of vacuum at idle.
Pulling 20" of vacuum on the booster made no difference with the brakes.
Booster will hold 20" all day long and won't leak down when applying vacuum through the hose to the check valve/booster
Brake pedal doesn't drop when I start the engine
Brake pedal doesn't drop after 30 seconds when engine is stopped.
After the engine is stopped and I press the brake pedal, the first stroke is soft and then gets progressively harder.

Forgot to mention, the kit comes with a 9" booster. I don't know what bore the MC is.
No light comes on when I check the prop valve with a test light.
Check valve on the booster only allows air out.
The pushrod is connected to the bottom hole in the brake pedal.
I adjusted the rear brakes out until slight drag was felt, then backed it off about a half turn (with the e-brake off).

I bench bled the master and have bled the brakes at least 3 times. No spongy pedal so I don't think there is any air in the lines. The pedal is firm, but takes alot of effort to stop. After the initial installation, and lack of brakes, I replaced the rear wheel cylinder, drums, shoes, and all 3 rubber lines. I also got plenty of fluid from all four wheels while bleeding. No change in the brakes.

I've read other posts where folks have had the same problem but haven't seen a solution posted.
Do I need to remove the check valve from the booster to check the booster?
I am out of ideas and open to suggestions.