going back to the Mopar Muscle header / manifold test on a mild 360, the equal length
headers averaged about a 15 hp gain.
I'm not saying they do or don't but, it's hard to believe just an h pipe could make anything noticeable.
Why is it hard to believe? You keep saying you don't believe. And people keep posting proof, dyno tests, race results, magazine articles. So tell me why you don't believe.
