i recently bought a gp pitts 1/3 scale. i bought the u.s. engines 41 as preferred in the instructions, then i read that this engine doesn't have enough power for full aerobatics! i have three engines near this size, but am unsure what to use. they are a quadra 52s, a miller 50, and a moki 1.8. i understand that some modiftcations should be made but i'm unsure what sort. any help that could be offered would be greatly appreciated.