No, you are exactly right. All I was saying before was to try it out for a while on the ground while breaking it in. Experiment with different props, because they make a big difference. Mine originally ran pretty well on the ground, and only showed signs of not being quite right once airborne. It may be that it wasn't quite broken in. I'll never know the answer to that. Just plan on running a few gallons thru it to get it right. I would put it in the air in another plane if I could, before going in the P-40. Things are always different in the air. As a last resort, it will run fine with a carb change, but you may not need to go there.