belive it or not, I happy with the way my 07 RKC exhaust sounds. I THINK it has stock mufflers on it. Niether side appears to have been drilled out in any way, although looking into the mufflers there is a difference between the right and left one. I think that's because the left is more of a resonator than anything? Anyhow, I've searched about with no results, but would like to know if someone out there makes fishtail tips that can be added to my stock mufflers?