Nice chart, just goes to show you how actual oil temps play a major part in viscosity choice, street machines - muscle cars and hot rods do not have, or fail to incorporate and oil temp gauge in many cases. Most every race car I work on these days do not even have a tach, just gear it to hit the chip when you need to. But they all have a Water and oil temps gauges, along with oil and water pressure gauges, and that's it, nothing else needed. My old notes stated only 2-5 psi drop max with the SFT centered EDM's, the offset EDM's a little more, and I've used .012 to .021 sized holes as well. Many get their shorts in a bunch for nothing on a "low" oil pressure needle, and in the case of SFT with EDM's, the climb is worth the view without question.