what should i replace the 2 mufflers with? I was thinking 2 flowmaster 40 series or 2 magnaflow mufflers....What do u think? Can they just replace the 2 stock mufflers with 2 aftermarkets and keep the tips? Which one will sound better and have better performance?

Can you put your year and model in your signature?

I personally prefer the sound of Magnaflow over Flowmaster, but I don't expect you'll gain very much if anything in performance. Most people can run stock exhaust on the 2k'* into the 13'* on the quarter mile.