What Gary Edwards said, plus I installed an engine with slightly more horsepower (140 HP Don George O-290-D2) and figured I'd need a little more rudder authority. Personally, I think it enhances the looks of the aircraft as well, at the cost of a few Kts, no doubt. I basically copied Clarence Grubs' 69CG because his aircraft was very stable with the added ventral fin and longer rudder. Sadly, both Clarence and his wife Edna are both gone now.