the way a PCV valve works, it is like a variable vacuum leak. while idling, just a little leak occurs. The bypass flow of crankcase fumes increase as the vacuum level decreases. All this is done with a check ball and a spring in the valve itself. So, if you have a normal PCV valve, (the kind that rattles when you shake it) It should go into the full time vacuum port. Usually, ported vacuum is just for vacuum advances or EGR valves. However this is just based on my knowledge, if the line to the canister is connected to a purge valve, I do not know where that specific line would go. (I think it would have to be part time operation)