ok i know some of you guys weren't sure if it cause more or less decel pop. Last year running the stock header with hindle slip on and PAIR still on I had loads of decel pop. This year PAIR removed and full muzzy installed I'm getting virtually none, unless I really try to...ie rev the engine to dump in a bunch of fuel and then slam the throttle shut. I mean trying hard too, so I'm happy. Keep in mind that my jetting has also changed since last year...it's still with a dyno jet kit but I moved up a jet size, will report if the swap with the holeshot stage 1 modified will make any difference.