The hose you will be Keeping There is certainly the valve cover ventilation and will be remaining open. Placing a filter on it would be intelligent to circumvent dust or debris stepping into your cylinderhead... I'm not very good at explaining this similar to this Obviously, but I hope it https://blacktop20v4age71470.dailyblogzz.com/33055090/4age-blacktop-for-sale-can-be-fun-for-anyone