Contemplating doing a "poor man's" Stage I and sticking with the HD Screamin' Eagle air cleaner and pipes. Not really a fan of loud pipes so I'm mainly looking to richen up the engine a bit and remove the airflow restrictions in place on a stock bike. I like the sound of V&H Monsters and everyone likes Rinehart's but they're both about twice as much as the SE pipes. Maybe someday down the road. Anyway, messing around on the HD Parts and Accessories site and I've come across two SE Street Performance listings: 1. Screamin' Eagle® Street Performance Touring Mufflers MSRP $390 P/N 64985-07A Screamin' Eagle Street Performance Touring Mufflers | Harley-Davidson USA 2. Screamin' Eagle® Street Performance Slip-On Mufflers - One Piece - Slash Down MSRP $370 P/N 80491-07 Screamin' Eagle Street Performance Slip-On Mufflers - One Piece - Slash Down | Harley-Davidson USA The first one is more expensive and requires you to purchase end caps separately. The second one specifically says it's a Slip On. Can anyone explain to me what the difference is between these two systems and any comments or experience with either of them?