According to the referenced article, the C&L intake manifold flows no less than 317 cfm per port. That calculates to no less than 2536 cfm for the entire manifold. WRT the BBR article, it does not state whether the 225 cfm flow is for one intake valve port, for the 4 intake valve ports in each head, or for the 8 intake valve ports in both heads. However, the following article shows a flow of 156 cfm per intake valve port for the 92-98 4.6L 2-valve heads. 4.6 liter Ford Engine Cylinder Heads Hence, one can intuitively deduct that the 225 cfm flow in the BBR article is also per intake valve port, or 1800 cfm total flow for both heads. Hence it's quite apparent that the flows of the heads and the intake manifold vastly exceed the flow of the stock air intake, and thus calling them bottlenecks is a gross error.