I have a '04 Grizz and it's bone stock except the hand grips and throttle ext. I just bought a K&N filter and four UNI plugs for the airbox. The reason I did this is because I noticed a heck of a difference with the airbox lid removed. I am also planning the stock pipe mod in the near future. I live at 8000' and was wondering if the factory installs a general jet that is supposed to be decent in all altitudes, or do they consider where the quad is being shipped? I want more bottom end cause the grizz don't want to wheelie at all unless the airbox lid is gone and I hit a small jump and punch it.