Picked up my '03 FX4 Supercrew from the shop today...I had a custom made dual exhaust with an X pipe and Vortec mufflers installed. It sounds great and seems to run out smooth. I had cats on both sides so it's true duals. Not cheap...$700 but it looks like he did a great job. Wish I would have had my digital camera with me when I went to get it 'cause it was still in the air. Maybe I'll crawl under it...