The breather is the inlet for the pcv system. For it to be dead correct, it really needs to connect to the air cleaner with a hose. Here is a proper PCV system. View attachment 1716085651
My original 340 air cleaner housing has the breather tube fitting in the side, thus not filtered air. Since there is filter material in the part that pushes into the valve cover, guess it is not a big deal.
