40 years experience porting cylinder heads and intake manifolds, and I take exception to one statement made by one of the posts. Velocity is critical if you want an engine to be responsive at low speeds, and velocity is important for total cylinder filling. Any time the volumetric efficiency exceeds 100% it will need velocity as well as shape, and size optimized. I have had engines produce as much as 123-124% VE, and produce near 2.1 hp/ci with heads that were mapped on the flow bench for velocity and flow. Boss 302 heads are neat heads for their time, but there are much better sizes that are smaller that flow much more air than a well worked/ported Boss iron head. The C302B head routinely flows 380/270 with 2.19/1.71 @.750" when ported properly. I recently ported 2 sets of the new aluminum Mummert Y-block heads that flow 280+cfm through a 1.940 intake valve, and 210 cfm through a 1.540 exhaust valve without a pipe. Was velocity important? Definitely. On the dyno, the heads helped make over 504 hp, on 352 cubic inches of Y-block. Joe-JDC.