Power Brake with strange behavior

[Super-Bee-69]

I have a problem with the brake after converting to the 496 stroker.
The Brake Booster was very much in the years, as well as the Master Cylinder. So just replaced both and made an upgrade with good parts! But the braking behavior is the same. Decelerating slowly, as if you were driving towards a red light, you have to really step on it towards the end so that it comes to a stop. If one chops from faster driving purely, as if one must make a full braking, one bites into the steering wheel - however the engine shuts off!! And will always do, with stronger braking.
Tank of course filled up. Then pressure Hose clamped off, but with the same result: Engine off!
What could be the cause?

 

[Super-Bee-69]

As for the braking power, I suspect that it gradually gets too little vacuum at slow deceleration and you therefore have to pedal as hard as without Brake Booster. From full speed he has by the speed much negative pressure.
These are my thoughts.

 

[Potts]

What's your vacuum?
I know inconsistent vacuum from a "lopey" cam can play with boosters.
Did you see the earlier thread on power booster issues from 747Mopar?

 

[Super-Bee-69]

Didn‘t see that thread. I also will check the vakuum at idle.

 

[Super-Bee-69]

Maybe I need an electric vakuum pump, like this??

https://mpbrakes.com/accessories/ac...f0b3e6cd|54742b77-d4cb-4e6f-b345-9d2ae635d5b6

 

[Super-Bee-69]

Or better a vane style pump like this?

https://shop.aerospacecomponents.com/vacuumpump3-vanebare-1-1-2.aspx