Ann, Im running an OS BGX on the Pitts. The prop has been balanced, and fits snugly on the prop shaft. First flights were with an 18/12, but later I switched to an 20/6-10. I mean no disrespect with this statement, but feel you will hearing more wing seperation stories now that warmer weather is here. As I stated before, I am having machined parts made that will replace those steel brackets. Since I have a strong desire for a "lasting relationship" with the Pitts, I am going to open up the upper wing to inspect the construction and see if it is adequate to support a modified cabane brace. I think the GP Pitts is beautifully finished. Its light and appears strong, but the affects of high frequency vibration cannot be underestimated. This plane is 1 of many giant scale models Ive owned over many years, and all the mishaps I experianced could be traced to high frequency vibration, specifically with the center sections of fuses. I wish you luck and sucess with this model.