Hi all! I am new here and love everything about this site! very informative and useful! I just bought a 2000 estate green ls v-8 7 months ago and she only has 60,000 miles. I got a warranty which came in handy because my right side valve cover gasket was leaking and is now repaired but i didn't have any driveability issues with it when it was leaking,i was just able to smell it burning off the headers.I just went to local muffler shop and kept the stock exhaust and had stock mufflers cut off and replaced with straight pipes in their place. i am only running the stock resonators and it sounds neat! The factory pipes from the manifolds to the ends of the resonators are all 2.25 then it crimps down into 2 inch for the tailpipes and mufflers and tips. Overall i noticed a good power increase with noticeable sound and even louder on full accelerations. i noticed no real torque loss and the car seems more responsive and quicker. my next plan is to get either an h pipe or x pipe and weld it in up front and keep the whole exhaust at 2.25 to help with the torque and small engine. the resonators will be replaced with slp loudmouth resonators and tailpipes custom bent to 2.25. i would go with 2.5 but i think it will hurt the cars performance and torque because of the small displacement and torque it has(267 ft lbs). Funny how similair these motors are to the 4.6's due to the fact they are both modulars. but we have dohc and mustang gt's don't. we have 50 cubic inches smaller motor than a gt's and only 6 horsepower less,however the gt kills us with torque (300+vs267). i have the sst tranny and love it! Tires are 245/45/17 and handle great!! I've owned 6 mustangs and i think that the ls handles the same if not better! ok sorry for long post and rant! just glad to belong to such a big and great community!