From a all motor honda stand point that is fair amount of power. Also like I said the bisi header peaked at the lowest rpm which is what I experienced in a real world environment. It is not just about peak power with all motor cars but the ability to carry that power as most h2b cars with cams,port work,real intake will shift at around 9-9500 rpm's at the track even with b series gearing and a tiiite final drive.
I have been around alot of these setups and tuned a couple 280+whp ones and the funky angle headers never worked on anything I tuned.
Conclusion its by far the weakest header design. Peaks the lowest makes the leatstpower and will not carry power outside of peak as needed for all motor drag cars.