I just sold one of my spare sleds last spring which was a 99'700. I bought it in a basket and rebuilt it. It never gave any problems and had good torque when compaired to the 600. They were hard on clutches due to their viberation at an idle. I set my idle up around 1700 and it smoothed the engine out and also made it more responsive coming off an idle. Keep the drive axel and driven axel greased. The motor mount by the secondary clutch was prone to breaking, so keep an eye on that. I had a fabcraft tunnel and changed the skid mounts a little and it really made a difference getting up on the snow.