I was under the impression that the regulator was needed when the tank was placed further aft ( at the CG ) that it was too far to push fuel with supplied pressure of exhaust. As far as the tank being too high wouldn't mounting the engine in the upright position correct this? Flooding is inherant in any plane when the engine is mounted inverted. Normally I will spin the prop several times after fueling before starting. It never kicks, spins a prop or runs backward.