I am getting many emails on the latest debate concerning a stock intake reworked over the stock Hughes Airgap. 
I have dealt with Terry and the fellas for many years and never had any complaints from them. I posted the Airgap manifold testing they did and mine. They even state it- "The torque with keg manifold was extremely strong and flat from the 2700 to 3500 where the FI-Air Gap matched it at about 3600 rpm and from about  4000 was much stronger."  So I spent time labor and money removing a VRP manifold, installing the Hughes and then installing the VRP Ported stock intake back in place. The point still stands, the longer runner stock intake, whether ported or not still makes more torque than any other manifold out there below 3500 rpm. Yes, the M-1 and Airgap make more HP at higher rpms. My dyno testing at API in Utah on the mustang dyno shows the AirGap and 12" Ported Kegger VRP with a 53mm Dual port TB. Hughes is the Green arrow. The Kegger had bad coil on this dyno run breaking up at 4600 (fixed now). If I am building for the drag strip and RPM, the M-1/Indy is the winner of choice not the dual plane. If I am building for trails and pulling, the long runner stock intake is the choice. The second graph is Hughes dyno (Performance Injection Equipment) and the first was mine. The Airgap passes at 4300 rpm and can be worked for even greater gains beyond that. But it took exactly four thousand, three hundred revs per minute to catch the stock reworked intake. 3800-4000 on the Hughes dyno graph. I do not build my setups for drag racing anymore, I run slow trails and pull RV's and quads. That is the core of my work now. Heavy trucks benefit from higher torque~ ask the diesel crowd.
Here is a great article from hughes on their testing-
http://www.hughesengines.com/TechArticles/1fiairgapintakedynotests.php