Depends on your riding and how into the project you want to get. There are several options as far as a deep snow track. The competition track actually works pretty good though. My personal opinion, the only thing I would get and I am running it on my pro is the challenger extreme 2.5. Some people say that you need to go with the 7 tooth drivers and do the chain case mod for the 2.5 to fit, but mine has well over a thousand miles with no issues. Although, if I had the extra money sitting around I would run the 162 x3 " CEXtreme, but then you will have to do the drop and roll for sure. As far as just the best bolt in track without any other mods, you can probably find a used Polaris 5.1 for a decent deal, and they work ok, just not as good as a true after market track. You also have the option to do the new peak track, but i do not believe anybody has had enough seat time to tell you if it actually works yet or not.
...
