I believe that the AEM actually Dyno's the most hp. (This is of, course, at the top of the power band.) If you can do better with the Shorty, then please let AEM know, I'm sure their engineers would be confused up the wazoo. About the Pro-M: I've seen some people get some serious gains off of it. I don't know for sure if it's more than the AEM cold-air. Do a search for some dyno figures. It's too bad they don't make a "big bore" AEM CAI.