[MrMagoo]

Thanks WTM, that saves me a lot of work, I was just thinking how little I feel like changing all of the hoses.

Sal, others who are interested:

Here were my sources for fuel bowl venting: "Holley Carburetor Handbook" by Mike Urich, page 7:

All bowls are vented to the carburetor air horn to maintain a constant "reference" pressure. This keeps airflow variations - like a dirty air filter - from upsetting the mixture.

Also this, from "Holley Carburetors, Manifolds and Fuel Injection" by Mike Urich and Bill Fisher, page 25:

Because the fuel bowl is maintained at near atmospheric pressure by the vent system, fuel flows through the main jet and into the low-pressure or vacuum area in the venturi.