This is a question thats impossible to answer. It depends entirely on who ported it, if they ported it based on a specific goal or if they just hogged the piss out of it. A ported performer is definatly better than a ported cobra. No one can say "only 10cfm" absolutely impossible to say. With what you have, i'd say your looking for a mild 300hp combo with 6000 max shifts. Leave the cobra. If you were serious about looking to go fast, then you'd need to change more than just the manifold.