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Honestly I don't know. I handed them off to my builder and he called me back a few days latter with the results. I'll see him this weekend and take a video.

Those heads with a 1.92 valve will flow right at 240cfm @28"...there is NO way they are flowing 220...maybe he's trying to sell you on porting? I've had many people flow our heads and 99% of the time there is less than 1% of change...