I guess the guys at my LHS were incorrect then as they said it should behave the way I initially described when I called them to ask why my engine would stall when I'd hold it nose down. In the video it almost seems in a dive the plane stopped accelerating, allowing the fuel to move toward the front of the tank. So I'm guessing in a powered dive situation with accleration the fuel would stay at the back of the tank? Also, I've seen some planes pop crow and go into a very long extended dive without stalling. I wonder how they achieve this if the inertia isn't enough to keep the fuel at the back of the tank?