Oil Underneath Intake

Double check- no, triple check that your valve covers (gaskets) are actually sealing- it's a known issue with air gap style (AG, Victor, S. Victor, etc.) manifolds that they have extra material above the runners (just in case you feel the need to hog the ports out more) and this material can and does keep the valve covers from sealing down like they should along the top of the manifold. Commonly people grind part of the offending valve cover rail away to allow the cover to tighten all the way down, but a good set of valve cover spacers will accomplish the same thing.