You have a lot of options here... The TT Pro-46 will accept any muffler that fits on an OS 46SF/FX. I have a
Morris Hobbies tuned pipe setup. I also have a Tower pipe and I've tried taking the baffle outta the stock muffler. The Tower pipe and removing the baffle both make more power, but transition suffers for some reason. The Morris setup makes more power plus transition is silky smooth. Haven't tried the the more expensive mufflers or a MCP yet (although I'll probably try all of them out at some point)...