Ski bolt to ski bottom distance is critical to maintain handling balance. If the USI have the mounts for your specific model this wouldn't be a problem. Otherwise pay careful attention to the ski bolt to ski bottom distance. (So says Snowtech Magazine) Had 301s on a polaris indy, worked great, very, very tough big improvement over the stock steel but brought model spec. mounts. Half the price of the USIs is the mount. Pricey. Back issues of Snowtech have an USI swap on a 700sx, I think. You might get some info. if you hit their site.