I may be buying a new truck and have kicked around the idea of converting my dually to a single rear. On the '03,is the dually fender an add on? Can I remove the fender and have a regular bed? I have a small gap where the fenders meet the bed and appears to be an add on. It would be nice to unbolt,rather then buying a new used bed. If I did convert,can I expect a fuel mileage increase? I've always gotten reasonably crappy mileage and would love an increase.