> The carb flow gauge - I have one I used on a Porsche 914-6
> ( 6 individual throttle plates and intake manifolds ) ...that
> tool  measures flow above the throttle plate.
>
> a vacuum gauge measures vacuum developed between the throttle
> plate and intake valves.

Yes, but....  With the plate closed, the "suction" the device
sees is the vacuum pulling through the idle circuit.  That's
what you are usually trying to balance with the Synchrometer.

Richard