When I was at a smog place here in CA, getting an emissions certificate for the Outback, the technician and I got to talking about trying to get carbed out of state vehicles to pass emissions. He told me that he won't automatically fail a car just because it has a different carburetor on it. But he will fail it if it doesn't have the major emissions hoses hooked up, which I know on my Weber on the SWB I don't. There's at least two hoses I can think of that need to be hooked up to something, in order to pass this visual inspection. There's that large diameter hose that went from the air cleaner to some gizmo on the exhaust side, and the valve cover breather hose (I have a small pleated filter element sitting on top of the valve cover vent now).

There was a thread on here about someone who made a template to match up a Weber carb top with the stock air cleaner base, so those hoses could be hooked back up.