Well (yeah you, Mr El Mirage wannabe
), I had the Ultra Sport, and I stuck a Magnum 75 ABC up front. The plane is capable of handling the speed (I'd say 'bout 105-110 mph), however, it's them cheap plastic cowls that don't like to go fast. Glass'em and you should be fine. The Ultra Sport's are awesome flying, and go where you point them with the right motor.
I'm not familiar with the Leo's, have you run this before? If so, what kind of numbers were you getting?
I say...go for it!
Gary