Data can be skewed on head flow. I have not tested a set of these heads yet. I'm trying to get them approved for my class. The intake volume is 20% larger then the Boss 302Rs and the Exhaust runner volume is 24% larger. This larger volume wouldn't amount to much if it weren't for the larger valves and put on a "large" bore engine. Some would be surprised what these new Ford heads flow. You thought the old 4.6/5.4 heads flowed well ported the Coyote heads outflow them stock in some cases.