the best choice would be to contact the organizer or tech inspector of the club or series you want to participate in. Would like to say only for a national or Rmax series you would have to run the new cylinder along with steal gears, new clutch, new air box plus an 8.5 insert in the carb and the specified jets. But I can’t. Safest way is to check for yourself.
LAD Specialties customer / tony kart / rotax / kt100