I am no mechanic but on my 15 SGS I installed the V&H header, Hi output duals, screaming eagle tuner and air cleaner. No Dyna, $1700. Did it before I picked up the bike (like you did not like the stock sound) does not backfire or have any issues. My old bike (Heritage w/103) did everything the same other then the tuner only remapped and it backfired terribly.