I don't see how there would be any pressure in the cowl, it goes straight through large openings behind the fenders exiting into the floor vents and out the bottom of the fender area. Easy way to tell is plumb a boost gauge in there. I bet you won't even see it budge off zero.

Jesse, the engine will only draw as much air as it needs. A simple example you can try, at rest while sitting with your mouth close breathe, then open your mouth halfway and breathe through it, then open your mouth wide and breath at the same resting rate. Your lungs won't get any more air as there was never any restriction, even with your mouth closed.

The only advantage you will see if potentially cooler air, and even then only if your cowl to hood seal is sealing properly. You'll get very hot air through the cowl if that seal is bad, particularly when at lower speed with the fan engaged.

 

I agree with you. I guess I worded things wrong. My opinion is yes it will only take as much air as it needs. But my opinion is that by sucking it through a bigger hole up by the cowl will make cooler ait and be easier for the engine to take that air. Just like if u breath through a straw vs just open mouth. Like you said your lungs only fill up so much so no matter how u get the air they will expand only to a point but open mouth is easier and less strain and up by the cowl to me is like if u stick ur head out the window while driving it's difficult to breath but turn your head around and it's easy to breath. Original hose under hood in my opinion is your head facing forward out window and up by the cowl is like turning your head around.

 

To be fair, off idle? Yeah, an IDI's getting a full charge of air. At 2500 RPM, though, your NA IDI is practically starving(and you can tell in the lost torque); anything you can do to get more air into that cylinder helps.

...Of course, why mess with small stuff when you can just take care of the problem? Add a turbocharger and you'll solve *all* of that high-rpm air flow issue.... because you'll be shoving it in real hard!
(It's pretty easy to see the difference in dyno curves, too - NA, the torque starts out high and drops with rev. Add a turbo and fuel to match? Now the torque starts out at the same NA level and goes straight /up/ till redline[or wherever you run out of fuel])