Near perfect isn’t perfect, but you said you wanted more response out of boost. You are heading the wrong direction. You will lose response with LSA heads at the expense of higher peak flow. This will have the potential to make the same or more power at equal boost levels, but since you are milling and running an inferior head gasket since your current ls9 is the creme of the crop unless going to thicker Athena then you are actually making your setup inferior and more likely to have issues then if you just ran more boost. The LSA heads also have different ports than the ls3 so they actually aren’t as good even though they are made with a different alloy.Near perfect isn't perfect. And I feel I can do better, is that ok?
the argument here isn't even about my original question, but others claiming how they would do it or how thier friend did it. I've already done the "add few psi" thing, I'm not downplaying other peoples builds, but they typically aren't at wot long enough to be concerned with adding a few more psi, as their A to B typically ends in 3rd or 4th gear. And will never see 5th or 6th and/or knows what happens up there.