I have an all stock 03 GT and I want to put an exhaust system on it. I'm thinking borla or flowmaster. How big of a difference is there between a cat back set up and just putting new mufflers on?
check out youtube you can find vids all day long of just about any setup you want to hear. Also try and use the search there are tons of exhaust threads.
+1 just get weld in's. People will argue that the aftermarket catback is the way to go because it has mandrel bent piping and bigger diameter. However, the gains are minimal and you can make power just fine with the stock catback.
I'm still running the stock catback with weld-in mac flowpaths...