I've put a Saito 180 in mine, and yes, it will fly the plane beautifully. Couple of problems, though. I mounted the engine inverted and found that the stock tank is way higher than the carb. This causes flooding and hard starting. So, I mounted a 16 oz tank behind the front seat, which puts it about level with the carb, where it should be. That required a very long fuel line run, so I mounted a 1 oz header tank up next to the firewall, and that solved that problem.
But, I used a 90 degree adapter between the head and the exhaust pipe to point the muffler down, and found that the aluminum adapter won't hold the steel exhaust pipe tight when everything gets hot. I think that adapter expands more than the steel pipe, allowing it to loosen. I'm still struggling with that one. If you do this, please let me know how yours works out.
Oh, the Saito is pretty light, and you will need to use over a pound of lead in the nose to balance it.