Heavy Breather!

I'm having trouble with crank case breathing. I have a 340 with a wild solid cam and Ansin (same as Mopar Performance) cast aluminum valve covers with 2 twist on filler holes. I've tried several different ways of vent, from an open breather cap along with or without an added PCV to the carb as but oil still spills out the breather. I also tried a breather vent to the air cleaner but it spills oil all over the air filter. Is something I'm missing, or is there issue I'm not aware of?