I found that the CB Oil filler/breather box leaks oil. (Part#1771) The leak occurs thru the two bottom machine screws holding the cover on. The threaded holes in the main body go all the way thru thus allowing oil to seep past the threads. Additionally, when the cover is removed, there is oil trapped at the bottom which spills out. This is where the lower screw is and is probably why it leaks. Of course a little silicone gasket sealer will fix this but at $70+ for this, I don't think it should leak at all. I removed it and went for a different one and a std. breather box with only valve cover tubing connected. The new filler neck had an opening for a vent hose but all I put on it was a small paper breather filter. Still, the Total Seal rings are holding back the blow-by for the most part.