Many car companies allowed raw air anyway.
Pontiac, for one, ran TWO choke lines: (1) first line from a fitting on the air intake of the carburetor (below the air cleaner, thus filtered air) to the heat stove, (2) the second line from the heat stove to the choke.
I never did like the cheaper set-ups where unfiltered air was introduced to the carburetor, but then no one asked me
In the case of the OP, either the hot air line MUST be installed, or the choke butterfly MUST be fixed in the open position; or the engine is going to run exceptionally rich, if it runs at all.
As far as calibration is concerned, the amount of air entering this area is limited by a restrictor in the vacuum source circuit to the automatic choke. Thus the calibration takes this into account.
Jon
