360 oil leak at back of intake manifold

do you have a functioning PCV system on the engine? I just can't figure out how you have so much positive pressure inside the block to blow anything out through the distributor hole or the rear china wall seal. Theoretically there should be negative pressure inside the block from the PCV system. My money is still on the oil pressure port back there... now there's some positive pressure where it's supposed to be and just full of oil.