I want to drill the orifice too but Im unsure how deep do I drill on both sides?
I had the exact same issue, except my breather exploded
I took off the breather and uncapped the drivers side as well, as I had all kinds of issues, oil leaking from driverside head gasket in addition oil inlet, and lots of fumes like you probably experienced. It was not discussed about drilling the holes until a month ago or something.