well i have said this about 3 times in the past few days. if you are looking to just replace the mufflers, the ones i used are the deltaforce 1 chamber flowmaster and it will fit into the space where the stock one come out of. now i can't tell you which others will fit and what they cost. but the deltaforce 1 chamber flowmaster is 72.00 at summit racing .com. and they sound real good at idle and all the way to wot. if my son ever does come back over i will see if we can make a video and post some sound clips. now my car isn't fast and it doesn't matter if it is. sound is what i am looking for and what i have gotten with the deltaforce flowmaster is perfect and the fuel mileage has definately came up with the settup i put on my 04. hope this helps.