i have a 2001 500 scrm 2x4, i have heard and seen some say high output, is there a difference, or are all 500's HO?

 

there is a HO and a non-HO. The first 1 or two years of the 500, it was not HO. The 400's were smoking the 500s in races, so Polaris rethough. They redesinged to 500, calling it the 500 HO. Up until either this year or last, they are not HO, because they changed a few small things, like the shocks, so they do not call it the HO anymore. Hopes i helped..

 

98 and newer 500 scrams are all HO