I live in Mobile, Al. The service dept at Mobile Bay Harley advised me today that I could put on 1.75 Rush slipons and do nothing else to my 07 Sporty and it will not run lean. They said they have put them on a new Sporty and checked and it is safe to run them with no fuel pack or anything else as long as I don't change the air cleaner from stock. They said the 1.75's are the same baffling that is in the stock mufflers. The way the Rush are designed they are just louder. Any Teck's out there that agrees with the service dept and service manager here in Mobile?