[12Ounce]

OK, I perhaps now understand your question about the lower intake manifold and gasket. The front cover has both coolant passages and high pressure oil passages going through it ... coolant pump and oil pump mounted to it. But I don't remember exactly the lower intake .... does it only have coolant passages and not high pressure oil? I think that is the case.... no high pressure oil. As far as coolant pressure aways being higher than intake (crankcase?) pressure ... think of what happens at start up before the coolant is warm. Remember a coolant leak could be directly into the crankcase ... and not thru the intake system.