you talking about the full cat back vs the direct bolt-in muffler? if so, the muffler only is just that, the muffler with correct extensions to bolt in directly with no mods. sound wise, the catback will eliminate the resonators. the muffler only will leave them there. in theory it should be slightly quieter and/or less drone with the resonators. either one will be pretty loud though. the outlaw muffler is basically a super 10 muffler. i debated between the outlaw and american thunder bolt in mufflers and settled on the american thunder. its plenty loud, IMO, for a daily driver.
