My scratch built Stealth is also tail heavy. In fact on the maiden flight I had to add 4 clicks of down elevator to maintain level flight when upright. When I go inverted the airplane climbs out quite a bit. This gets worse as the fuel tank level is reduced making landings interesting to say the least. It is just something I will need to get used to. But the flat spins are awesome!! I had to add about 80% expo on the elevator. Helps on landing.

Tom...