As far as I know the owner never has put it on the strip. Lots of street racing.
What I do know is, that every time I opened up the cross sectional area of the intake port on the cylinder head, the power went up on the dyno. So it appears to me the header wasn't the bottleneck to that point.
Interestingly enough was that in back to back tests on the engine the Summit Racing $129 (at that time) 1-5/8 long tube header made only one less average horsepower from 3,000-6,000 rpm than the TTI step header. Above 6,000 the TTI was better.
What would happen with a bigger header tube I cannot say. I will only report what I have actually tested. Anything else I might have an opinion on should only be considered as BS by me.