My Sextra has a K&B 61 and a perry carb, swinging an apc 12-6. I modified the tail by making the vertical 1" taller, the rudder is 3/4" wider, the elevators are 3/4" wider, and all three are aero balanced like a Goldberg Ultimate bipe. I have also added a full length dorsal fin, which really helped the knife edge. This plane is definitely 3d capable, and is the most fun to fly , most aerobatic plane I have flown to date. I have broken the fuselage in half twice, but will always fix this plane if it's possible.