i'm not good with name brand mufflers. all i can say is if you go with a performance exhaust is DO NOT GO TOO BIG! coz it's gonna sound like a fart can UNLESS your 3TC is fully built and you're running dual carb set-up... you wouldn't care about the exhaust coz all the sound is coming from the front, hehehehe! nothing can replace the sound of dual webers revving.... oooh!
stock set-up don't go over 2" piping, just my opinion!
here's another pic for you... (3T base motor with twin spark plug turbocharged twin cam motor, oh and it's chain driven not belt

)