I'm thinking about designing a custom airbox for my KZ750H3. What I'm trying to figure out is the total area of access to air in the stock box. Under the filter cap is a plastic stem with a number of small holes in the sides. Other then the crankcase breather hose, are these little holes the total access to air that the filter has? I assume that the stem goes all the way through the filter, blocking off any other access to air. Is that right? Thanks!