When your jeep is cold it closes off air flow to the carb. so your engine warms up quicker, for the purpose of emissions, utilizing heat from the engine that comes from the hose under the air intake of the air cleaner that you really can't see in this picture. Take the hose off at the end of the air cleaner and you'll see a flap that's connected to the mechanism that controls it opening and closing, by temperature and vacuum. When the engine is cold the flap will be in the closed position. Most if not all engines, pre 1968, did not have this mechanism. It's strictly to limit exhaust hydro carbon emissions for a cold carbureted engine. If it doesn't stay open when the engine is hot it's not working properly.
My post was in response to Kik's correct post. Navychief's exploded diagram will list the air cleaner related parts, but after Nuttering none of the air cleaner parts are absolutely needed.
As long as you can get past your emissions inspector, you can run a nice aftermarket cleaner without provisions for stove air. This due to the electric heating element in the floor of the intake manifold.
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