Do you have a sand seal or no? There will always be a little weeping from oil mist through the crank slinger, even if you have the best breather system in the world, on a modified engine. Stock engines are pretty good and oil free, but modified engines move way more air due to under the piston swept volume. So since they move more air, the oil gets foamed up more.
RE the oil weeping from the oil pump: if you dry sump your engine you don't have to worry about sucking air or oil leaking out. Dry sump pumps are sealed from the engine. They draw through the pump for each stage. However, they are expensive. And complicated with MANY more locations for leakage. I no longer worry if my engine is starving for oil on the track or street though.