340 motor pumping excess oil on right side

If that were true then you would have a lot of oil already pooled somewhere; either in the cylinder, or in the intake; and if that were true then either the intake is pulling oil up from the valley or you have a serious mechanical problem inside the chamber.

Are you 100% sure that what you are seeing on the plugs is oil?
i suspect the intake is sucking it up somehow need to do a full leak test perhaps