My 350 has the stock 2-bbl Rochester carb from '71 on it. On the back facing toward the distributor when we got the car was a small rubber hose (I'm supposing attached to something on the carb which would have to be a fitting), with a screw inside...I guess this screw is to keep this plugged up. Is this a vacuum port? What is the function of this? Our local carburetor experts aren't 'up to par', and as they rebuilt our carburetor just said, 'We left it in there because we have no idea what it is for'... Thanks for any help.

Are you running the "original" air cleaner ???
the hose connected to the hot air valve more than likely, I think :rolleyes:

That makes sense, the hose size would seem to be about the same size.