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Message: <blockquote data-quote="Silver95bird" data-source="post: 1404400" data-attributes="member: 21743">This may turn out to be quite a discovery. Maybe not so much for the NA guys, since the ratio of intake to exhaust isn't as bad, but for the NPI SC crowd it may help a lot more. If the exhaust flow is noticeably better on the 5.4L heads, then someone grinding a custom cam for an SC'd modular with these heads would run the smaller exhaust lobes and tighter lobe separation, netting about the same overlap - but how much will that shift the shape of the torque/hp curves? Also, even if sticking with an off the shelf cam like the NPI comp 262s or a stage 1 or 2 MHS cam, the better exhaust flow should evacuate more of the outgoing charge before the intake valve opens. This should allow more fresh charge in, especially if there's boost pushing it in. Will the increase in flow help reduce the temperature inside the cylinder enough to lessen the risk of detonation, or make more power in that next cycle? Remember at WOT the incoming fuel helps cool the hot spots down, and effectively the more that happens the more of the liquid fuel vaporizes as it absorbs the heat. Not a bad deal. If that next cycle doesn't have to fight the outgoing charge, more air should come into the cylinder given the same blower pulley/rpm. Any chance that reduction in backpressure (boost) helps reduce the IATs?</blockquote>