rcworld, What you refer to as the "stock" C/G point is just plain incorrect. It is "misinformation" printed in your assembly instructions and should be ignored. Somehow it got printed as 3.25" when it should have said 2.25". This happens in ARF instructions more often than it should. Always measure the MAC and caculate the C/G yourself. The general rule of thumb is to balance a model between 25-33% of the MAC, never more than 33%. At 3.25" with a MAC of 9", you were at 36% and damm lucky to get the plane back down in one piece. John's advice to set it @ 25% for this model is correct. Aileron differential is meant to help reduce "adverse yaw", a trait of Cubs. This will not fix a tail heavy plane. You must have the C/G correct. Aileron differential is at your option. To fly a Cub correctly (to overcome adverse yaw) you should learn to add rudder at the same time you bank it with ailerons to make a turn. A lot of flyers today with computer radios program in rudder mix with the ailerons. I am "old school" and add it in with my thumbs as I fly. Either way, some rudder should be used when turning a Cub, even if it has aileron differential. Good luck