I have a 2008 Ultra and have been having an issue with stock mufflers rusting and looking bad. I recently bought a set of mufflers that came off a 2008 screamin Eagle Ultra. I was wondering if these flow better than my stock mufflers as these are made for a bike with a 110 CI HD motor and I have a 96 CI stock HD motor. I really bought them because they look good ( no rust) and they are EPA certified quiet which is what I want but if they flow better than my stock mufflers that would be a nice benefit. Anybody ever use these? Is there much difference?