Four wheel discs, all bled properly, no issues there. Good high pedal with engine off. Start engine and the power booster has the pedal going practically to the floor.
My question : Is there any way to regulate the vacuum to the booster? I have tried vacuum from both the manifold and the back of the carb. Thanks.

 

Electric vacuum pump or a vacuum canister are 2 potential options - the electric pump would be a complete substitute for engine vacuum (provides a constant 18-20 lbs), the vacuum canister would simply store additional vacuum coming off the engine as kind of a supplement.

I had a really good electric pump (I think it's called a Bandit), but the downside of using one is if the fuse in its power feed line blows, you lose your vacuum supply, i.e. your brakes basically disappear. So I got paranoid and now the Bandit is back in its box on my shelf for now.

 

Your problem isn't "regulating" vacuum. Your problem is that the pushrod from the pedal to the booster is too long and is activating the booster air admittance valve. Readjust the pushrod. Be sure it is in the lower of the two holes in the brake pedal arm. If that doesn't fix the problem, then the valve in the booster itself is bad.