Just putting out accurate numbers from DIRECT testing.
Edelbrock tells us that bolting on a Performer or RPM intake to a Chevy 350 engine makes more power. OK, I bought into that BS for decades so decided to do some back to back testing.
Increasing runner size, height of the intake and plenum volume LOST power on a much larger engine with excellent flowing heads. How can as bigger intake help a tiny little 350 SBC making over 100-150 LESS HP?
Tell me how bolting an RPM Airgap intake to a 350 engine in a 1978 Chevy truck, or even a 1979 Corvette L48 or L82 makes "more power" than the stock intake that was removed? I woln't even get into the fact that the taller intake in most vehicles requires a drop-base air cleaner for hood clearance, which moves the lid closer to the carb killing off quite a bit of power with some set-ups (tested that deal too).
Let's even go one step further and say that they just "rebuilt" the engine and added an "RV" cam like 95 percent of the "population" does with these things. Tell me how a bigger/taller intake magically improves power (torque), average power, and makes the vehicle faster? Even your post above says that the Marine intake makes more power in the 4500-7000rpm range. Most 350 SBC builds woln't make power much past 5000rpms and even with good heads and most of the cams chosen these days are DONE before 6000.
The engine in my Ventura is also set-up to test intakes, I remove the water crossover from the intake so I can swap them in about 5 minutes at the track. I've tested as many as 5 intakes back to back at private track rentals on several different occasions. The only intake that ran close to the iron intake was the Tomahawk intake and it took a 1" spacer to do it. The "modified" iron intake actually ran quicker in short times and ET, the big single plane intake ran nearly 2 mph faster on top end but still got outran by .03 seconds in ET. For reference the intakes I've tested were the Performer (complete TURD), Performer RPM (very good intake but the drop base air cleaner KILLED power so I had to make a custom filter for the Shaker opening and ditch the lid), Torker 1, Torker II, Holley Street Dominator, P4B and Tomahawk (aftermarket single plane designed by Dave at SD Performance).
What the big Tomahawk intake and spacer did was "shift" power and pull harder in the upper mid-range and top end, but lost average power/power in the loaded RPM range.
None of this matters much in the big scheme of things, Edelbrock has the entire population brainwashed into thinking you can spend $200 on one of their intakes and go right out and pull bigger wheelies, longer burnouts and run quicker times at the track. About the only true statement they make in their advertising is that the new shiny part removes some weight from the front of the vehicle.......FWIW......Cliff