I have a question about 455 cylinder heads, I understand that the Stage 1 heads flow more, but you guy's are always saying put stage 1 valves in standard 455 heads and they are the same!!! How can that be? The flow might be the same but the velocity will not be, unless its the vary same casting!!! I want to know what the flow cfm difference in both of them. I'm interested in this engine more then you know. I have soul heartly decide to see what is the difference's in the heads and rods. please respond.