A friend of mine put a .40LA into his and it flew it just fine. It did come out very tail heavy and he had to add quite a bit of weight to the nose, several ounces, I think. The .40LA is no longer made, but the .46LA weighs the same, so it would still require nose weight. You may as well add weight by adding more power. Either a ball bearing .46 or the Magnum 52 four stroke, if you want to go that way. I bet that even a ball bearing .32 will fly it great.

Good luck