Given the flow rate of the stock intake manifold, it does not appear to be a restriction on your typical stock or mildly modified application where the cylinder heads have not been modified. This is not to say that a higher flowing intake manifold "CAN NOT" improve performance over stock, but rather to confirm that the factory intake does not represent a measurable restriction on the stock factory cylinder heads. Because of this, we are not willing to "go out on a limb" and make ANY potential power gain predictions based solely on airflow. This testing shows that the primary user for an upgraded intake manifold on this engine will be using either ported cylinder heads, a form of supercharging, or both. These are the people who will benefit most from an aftermarket intake upgrade. People with completely stock engines MIGHT find some improvement, and we will be happy to provide exact details when they are available, but our initial testing has indicated that any aftermarket intake for this engine will only be ideal for more heavily modified applications