I have a modeltech funfighter P-51. I'm running an OS .46 LA with a MAS 9X8 prop. on the bench tuned for flight it's taching 14200 RPM. do you think if I swapped out the LA for a .46 AX and put an 9x10 prop on it, I would get a noticeable gain in the top speed or the added weight would defeat the purpose of the swap? right now the plane is an estimated mid 80's in level flight. I'd like it to be faster!!!