I like the black. My opinion, the RPM lmits of this motor will negate all but the highest frequency pulse, I don't think the small difference in pipe length is going to reduce power too much, it's not a YZF after all.
Since you're custom bending what do you think of twins- smooth black pipe from heads to slash-cut, with internal baffle and no seams? If you can build that I'd be interested.
