got a new "turbo" muffler installed and it sounds great ($75) - i told them i didnt want anything too loud and he said it def wasnt enough engine for flowmasters so they put one on that they said they use when someone comes in with a v6 mustang and want it to sound like a gt - cut up the old stock muffler with the sawzall and i think i might have found the mystery valve but not exactly sure how it works - ill take pics this weekend and put them up next week

side note: the stock muffler is a behemoth - very heavy - but i was surprised at how clean it was inside after 12 years