Cool, thanks for explaining. Sounds like you're planning on taking your 650L a BIT further than I plan to take mine. I want to just snag a street legal 02 650R, and go from there. I'll keep this as a traveler/prerunning bike, because eventually, I have big dreams I don't even have a header, just the back half White Brothers E2 setup. Will a header increase the db level a lot, because I'm already close to the legal limit here in California, and I get hastled even with my silencer in the pipe .