cool story. I had a 72 rupp magnum with a 440 free air. That sled had won the 440 stock class in eagle river the year before. My dads buddy was on team rupp back then and sold it to me. Not much by todays standards but it was the fastest thing in town till dad got his merc sno twister 400 free air. Which by the way used a Kohler free air motor too. those snow twisters still are competive in there classes in snowmobile drag racing. I still remember drooling over the modified free air tripples the team had. Allowette (surely spelled wrong) made some strong 3 cyl kolher powered sleds that you could buy off the dealership floor. I believe too the original 4 cyl king cat 800 was a free air kohler motor that only a few were made for racing open class.