[Cupfan]

But WHY?

Bullitts have the ability to suck in and expel more air. It's there in black and white with the intake, throttle bodies, and Arvin mufflers.
More hp in lower ranges is not the answer to this question.
What is?
How could any of these three be a detriment?

 

[Cupfan]

Well, going the other way, if stock Bullitt's are dyno'ing at around 280 and the GT's really make what Ford claims, then I'd go so far as to say that 20 hp IS marginally different and should show up at the track.