Magnaflow Mufflers??
Magnaflow Mufflers?? Just bought an 05 GTO. I am the 3rd owner, but I guess the 1st owner welded in magnaflow mufflers and removed the mid-resonators (2nd owner had no idea until I told him after the sale).... I am looking to upgrade the entire exhaust system. I was going to go with a cat back magnaflow system or borla, but am I going to really see a difference in sound or performance?? - Or should I just throw in headers and put the muffler money to something else??
You're not going to gain any performance going with a catback, maybe 1-3hp at the most. Sound will change depending on what mufflers you get with the catback but personally I don't think speding $700 for 3hp is worth it. Spend that $700 on some headers and you'll get 30hp instead.
why not go true duals?? 
I put a clutch in a friends 05GTO and the stock exhaust looked like at least 2.25 with an X in the center. I'd say stuff some headers on and try it. Might be ok with a stock engine?
Mid resonators are replaced with two separate pipes. Don't I already have true duals then??
you already have true duals on the 05. I would make sure you have some sort of crossover. add an X-pipe where that mid resonator was. The Stainless work's headers are really nice. I had a set on my 06 and they fit great. Borla sounds badass but if you've already got mufflers on it, I would save the money and put it elsewhere.
