I've got an 07 YZ450F with the stock exhaust set up with the Pro Moto Billet Spark Arrestor and 96db end cap when needed. I also have the 48/170/GYTR fuel screw combo, 50 tooth sprocket, Twin Air Power Flow Kit, and GYTR Off Road Flywheel. I was thinking of putting a new exhaust on my bike, but I was wondering how bad the stock exhaust really is. Since I've made these improvements the bike already has more than enough power, so would a slip-on exhaust really make a huge difference, given the power improvements I've made already? Is that extra 3 or so hp worth the $$$ even though the bike already has more power than I need?