There is a PCV orfice in the intake manifold. The rubber hose from the left(drivers) side valve cover connects to this orfice. The orfice is supposed to be 1.5mm (.060") in dia. But it sounds like the oil is foaming & causing the level to rise. I would want to change the oil & make sure that the level is correct with 8 qts of fresh oil! Possibly the oil is being diluted with fuel? Happy Holiday