Early A Gas Caps-Vented or Non-vented?

All tanks have to vented in some way. In about 1971, the vent was run to the front and terminated in the Charcoal canister,(great idea). From there the intake pulled the vapors up, thru various controls. But
That metal line was very small (bad idea) and after a few years would rust up, leaving you scratching your head when the engine stalled for lack of fuel.