Sounds like you're on a mission to prove the majority wrong, so let me add a few points:
-You're "experiment" is completely unscientific.
You made dyno runs on separate days, months apart- although you may think the conditions were the same how do you know? Do you have accurate measurements for barometric pressure, temperature, and humidity for both runs?
-You're dumb enough to run your car without an air filter... and then point out to us that it made more power without any filter at all- Duh!!!!
-You attribute 2-3 tenths at the track to switching to the stock filter. i don't think so
-Did you consider that your
k&n possibly got dirty between October and now, causing the horsepower loss?
- I think when the guy said to add 33%, he didn't mean to add it to the corrected numbers- your stock mustang is not putting out 296hp to the flywheel
I don't think anyone here thinks that a K&N is a world beater- but countless dyno tests have shown that it does give a slight advantage (2-3hp) and outflows the stock paper filter.