I am about to go to the hobby shop in about one hour. I don't know if I should get a .50GK 4-stroke or a .56GK 4-stroke engine for my new Hangar 9 Piper J-3 Cub. Money really isn't an issue and I don't know which I should get. I guess it is ultimately up to engine availiblility at the LHS. Also, what kind of fuel is burned in 4-Strokers? I'm a 2 stroke kinda guy and use 10% Nitro Glow fuel religiously. Will I be able to burn this same type and mix in my soon to be new Saito 4-stroke? Any help here would be great. If no one replies I'll just ask the guys at the shop, but they are too concerned about the dollar and not my plane, so there's no telling what they will recommend.