The center port in the head ties into the exhaust port, the flapper in the manifold routes exhaust from that side, thru the intake to the other side till it warms up and the flapper opens. With headers the flapper is moot since headers do not generally have them.
A vacuum and a screwdriver is all you need to clean those ports out.
I, personally, have never seen it plug up and I've been fooling with Mopars for 30+ years. Some say it happens, I wonder why?
They say there are no such thing as a stupid question. They say there is always the exception that proves the rule. Don't be the exception.
