I've got Mustang 3.8 TEMs exiting 2.5", y-piped to a single 3" Moroso Spiral Flow, y-piped back out to dual 2.5" Magnaflows. Has a nice sound to it. Not ricey at all but not quite exotic sounding either. No buzzing or resonating in the slightest....at least that I can remember. It's been a few months since I've driven my bird.
Off hand, this is the closest I can find to how it sounds: http://www.youtube.com/watch?v=OhNIeZ7FzwU Imagine it more......."American" sounding and deeper though. I'll have to try and get a video later if you'd like to hear it.
Edit: BTW, mine is also a 3.8SC.
1991 LX Thunderchicken
4 wheels/tires, A motor/ transmission, few seats and gauges
Yep, she's got it all
Well I have peeked under the car but I have not been under the car yet and the guy who sold me the car showed me receipts for the exhaust. I think there are universal high flow mufflers.
Lil friendly advice. Put the car up on jackstands. Get under the car and look around a bit. Not just at the exhaust but at everything in general. Not only would that allow you to perhaps decipher some part #s (if visible), but also you'd have a better ideal of your car's exhaust layout in general so when someone suggests a part,you're not left bewildered wondering where it's supposed to go. Also, pop the hood f you haven't already.