I don't have such a diagram, so the paragraph below is just an educated guess.

Any port on the base of a carb is usually considered "ported" vacuum. That means it usually doesn't supply much/any vacuum until the throttle is opened. It is mostly used for vacuum advance at the distributor.

'57 GMC 102, Original 347 V8, HydraMatic, 3.08 rear gear, added A/C, disk front brakes, HEI, AFB carb, '98 Honda Black Currant paint. T-boned and totaled 10/12
'52 GMC 152 Stake Bed, Original 228, SM420, added A/C, HEI, disk front brakes, '67 Chev 3.55 rear gear. Gets used as a real truck.