I see all kinds of flow numbers. Pictures of pretty ports. My heads are an old set hand ported -1's by Jeff at MCH long long ago. I touched the valves myself at my buddy's shop. No flow numbers. The runner walls look a little wobbly. I do know that the 572 with 2 eddy carbs on a cross ram it's been 9.04@149 at 3350lbs. How much do they flow? how much power? I can only guess. But I'm happy with the results. You never know until it hits the track.
Doug