Oil Leaking From Dipstick

Pull the PCV valve and remove the oil fill cap on the valve cover. Rev the engine and hold a tissue over the opening and note the blow-by. A pressurized crank from ring blow-by is the only thing I can think of that would cause air flow out of the dipstick tube. It would have to over-power your PCV valve. If little blow-by, then suspect the PCV valve isn't correct or working, or the tube at the carb is plugged.