rev is a must for a 220, I have a 03 220 and this made a huge difference in mine, sound, performance and everything. I didnot notice a lot of low end loss with it either, it still runs great through out the rpm range. I am still adding to it also, I have sent the carb to RB Designs and am waiting for it to come back, while it is out I am installing Delta Force reed valves and cage. I am considering a FRP torque ring to have around for different rides ( if this thing does what it says). anyway good luck with your bike, Kevin