Is this a flaw in my intake?

The metal tube goes right through the manifold, no exhaust enters the carb just heat............

 

A common misconception in that exhaust gases flowed up the tube and into the carburetor choke. In actuality it is air heated by p***ing through a p***age in the heat riser port, and it is that hot CLEAN air that actuates the bi-metalic spring in the choke, not exhaust g***es.

Look in the port to see if the two holes (upper AND lower) are connected by a cast in tube. If that's the case, and I suspect it is, you need do nothing but plug in the choke stove tube for the choke on your carburetor. If it isn't, and you are going to run an automatic choke, simply press a tube in the manifold to connect the top and bottom holes and provide a place for the choke stove tube to insert.

You might need to enlarge the holes for a tube of sufficient size to accept a choke stove tube, although stock choke stove tube would have been swaged down where it entered the manifold so that when it was bolted on the choke it would be tight and not rattle.

It isn't needed if you are running a fully electric or a manual choke, of course, and making sure exhaust in't p***ed to the outside is all you need do.