Open breather on one side is incorrect. The valve cover breather for the PCV system should be a closed type with a hose nipple that gets a hose routed from the breather to the bottom of the air cleaner. Then you will have a complete PCV system, instead of gettin that "buildup" all over your valve cover from an incorrect open breather. You need a complete PCV system, not incomplete.
Something like this for the under side of your air cleaner:
Breather Fitting
Something like this for your valve cover:
Breather