If it sources below the throttles its manifold
If it sources immediately above the throttles its ported.
Many Qjets had a higher vacuum source just below the boosters that was a venturi vacuum. It was used for multiple reasons over the years, most of them dumb
Some Qjets also have a positive flow source above the boosters on the secondaries that should not be confused with a vacuum source. Its a positive flow that draws warm air over the Thermostatic air door in the snout of the air cleaner.