crossover or x-pipe

If the car is consistent there is nothing wrong with the dragstrip dyno. Not to mention it's cheaper and more fun.

a dyno's value is in proving change.The number does not mean much...but when you change a component it will tell you instantly how the engine output has changed,as will a time slip if the change is big enough.
...and I know guys who claim they could "feel" the increase after installing an H pipe?