Getting Vacuum in a flathead

I'm adding a power (Vacuum ***ist) brakes to my 8BA flathead powered 51 Merc.

Normally, on the flathead, the vacuum line is tied to a vacuum "pump" that is attached to the mechanical fuel pump. However, I'm not using that pump. I have an Edelbrock 3 carb manifold with three Strombergs. The center carb has a small vacuum line attachment tube on it. Is that enough vacuum to power the brake unit.

Thanks for any insight here.

Tequila Bob

 

No, I would tap the manifold ,preferably in a plenum area that is fed by more than one carb, Im not sure where that would be on a 3 carb edelbrock, do they have a common area or all seperate runners?