Took a chance and ordered the Rev 9 exhaust. I wanted something really free flowing that I could modify but also wanted stainless. It's 201 stainless which I know is not as rust resistant as 304 but as I live in CA, rust is not a problem. I put it on and the drone was unbearable at 3000 rpms but based on the design I knew it would be. I then welded a stainless 9 inch resonator that I bought for $30... Huge difference. I have the Dizzy E30 tune with out pops but it still pops between shifts and during down shifts. Tone is excellent. The clamps are terrible but I Just welded it together myself with some flux core stainless wire. In my opinion all exhaust clamps are worthless. So for $360 I have a full 3 inch CBE with minimal drone made of stainless. I may change the resonator to 12 inch to bring down the drone further but we will see how it is after a few weeks.