Can you PM me some more information about the setup that these heads were intended for use on? 302 or larger? cam? flywheel or rearwheel hp that was expected? max RPM for intended use? more for street or racing---or best mix of both? I'd like to make a significant jump up from my ported GT40 heads right before I add a supercharger and I think these would put me over 500rwhp (with a Vortech V3) but the car is street driven more than it is track tested.