dialing my 318 in finally!

I'd say we need a photo of your carb. Maybe you have the wrong port. The other possibility is that either the metering block/ body has a plug or a flaw, or even a bad gasket.

You are right, a ported vacuum fitting SHOULD bring up vacuum as you drive around. You should also be able to bring up RPM to a "high cruise" setting, hold the throttle there and observe vacuum