I have seen lots of posts for FI bikes, so I'm unsure of how much difference there would be for my '04 883. What kind of sound difference is there between the 2.0 and 1.75 Rush slip ons? I don't want the bike to be obnoxiously loud, but definitely louder. I might not do the full stage 1 swap out right now, but will do it later down the road, for whatever difference that will mean between considering the 2.0 or 1.75. Can anyone share any tips on the loudness / performance / fuel leanness for the 1.75 or 2.0? Thanx.