Parts manager at dealer says I could put 2.5 inch Rush Big Louie mufflers without a tuner on my 2012 Ultra. I had 1.75 inch Rush mufflers on my 2007 ultra and it sounded good and ran great with no tuner. He said because of the cats, the 2.5 baffles would be about the same as the 1.75 on the 2007, maybe quieter. I read all the posts about backpressure and want to know if any one else tried this without a problem. I plan on a tuner and intake after I'm happy with the sound. Thanks!