duels on stock 225

Speaking of that, whatever muffler you wind up with, make sure to use very soft hangers. The hook-and-O-ring type, for example. Today's popular "rod and rubber box" type transmits a lot of noise to the passenger compartment.
(Tailspout outlet 45° or greater downward.)

Excellent info as always, Dan. Thanks for the help. I'm about to do the exhaust on mine as well, and I've got a true dual Dutra Duals setup I'll be running, so this is quite helpful.