I went with the Dunstall Reverse Cones and I'm starting to love the sound, I bought mine on ebay and the measurements were miss leading, I cut my headers and used a reducer 1/2 to 1/4 I think, but my problem was the reverse cones were bigger on the end that went over the reducer, I made it work. don't forget the rubber stop on the exhaust you take off, I made my own so when your center-stand comes up it would hit your mufflers.