The Dazzler can do 3D. The fusalage is a little on the short side,andthe roll rate is extemely fast unless you tone down the throws,so you'll find that torque rolls and harriers might not be as easy to control as they would on some other planes like an Extra or a Yak. But with the right engine, a Dazzler can hover and do most other aerobatic manuevers very well. The TT .40 is a good choice for sport flying on the Dazzler, but is not going to be enough engine to do much 3D. If the Cub you refer to is a .40 sized cub, that's where I'd put the TT .40. If you are limited to these two engines, then theMagnum .70 is going to be a better choicefor3D.However, if the Cub you are refering to is a .60 sized or bigger, then that's where you need to put the Magnum .70, and get an O.S. .55ax or a .70 to .90 sized four stroke to do 3D on the Dazzler.