Check out the Marvings conical exhaust on MonsterParts. They're under $600 for either the low mount or high mount.
Here's my SevenFitty with high mount. I'll be ceramic coating that exhaust soon.
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I made my decision and just ordered the Marving Conical just like this one, but low mount version from Monsterparts. Thanks Jeff, can't wait to install it. I will also post some photos of corse.