Hello everybody and thanks in advance.
I am removing my smog suppression system while replacing my valve cover gaskets and some other things. I have all the holes in my manifold plugged except for the one in the picture. This aluminum type hose comes off and leaves a nice big hole right there in the manifold. I should have gotten a picture of that too. Sorry about that. But does anyone know how to plug this? Is there a cap I can buy or something? Thanks guys.

 

That "hose" is actually an air duct. It feeds the factory air cleaner with warmer air when the engine is cold to help the carburetor atomize fuel better until the intake and carburetor are warmed. Then the air valve in the air cleaner ***** and draws cooler, more dense air. it's not exclusively a "smog" thing but as much a driveability thing. It you are keeping the factory ait cleaner, you should consider keeping the air duct since it costs no power, is not a restriction, and actually helps operation.