I was called and asked if this was so why don't my regular valve covers leak
oil with a short or flush fill cap? Well the more STOCK looking covers have a baffle built into the area just below the fill cap/breather. This baffle is not present on the RACE covers because they would interfer or hit the stud girdles or high lift or a big rocker ratio. Before all this cool K & N stuff was available we used to braze a piece of screen across the bottom of the tube near the valve cover and then steal the plastic scrubby ball from the wife that she used to clean pots and stuff 2 of them in each tube.