The North American T-6, "Two of Hearts", flown by Mary Dilda. The T-6 class produces a lot of close racing, since all the airplanes are essentially stock. Some are more 'stock' than others, though. If you walk up and take a close look at the airplanes, some seem to have undergone a program of wing smoothing and other aerodynamic cleanup. Little things like how well the gear doors fit when closed and whether the leading edges of the wings are filled and sanded under the paint make a difference on the race course.