I have the same set-up that you have. My guess is you are missing the plate on the inside of the Lemans valve covers like vettestr mentioned. I have also heard that running the PCV on the drivers side instead of the passenger side of the motor can cause this, but I don't know if that is true. Also you may want to check and see if the PCV is stuck open. The amount of
oil you are sucking into the intake through the carb is probably minimal and I would not worry. I have more of a problem with those Lemans covers leaking
oil all over the heads and smoking!
--Mike