hemi advantage?

It's not the shape, and look at the pictures, not even close to 1\2 a sphere ever. So a 426 has a 4.25 inch bore which means for a true Hemi that center of the dish would need to be 2.125 inches deep. Anyway, what makes the power is the crossflow valves arrangement intake on the intake side and exhaust on the exhaust. That is what NASCAR outlawed.