OK,, if you bought one of those S-90K's you could use a 3 Blade Prop on it, the S-90K's Engines run best at 11,000 to 12,000

as for Braking-In a Ringed Engine, just running them a bit rich for a gallon will be good..

BTW, most stock Glow Plane Engines in these sizes will happily run on 15%, and Heli Engine will run on Fuel as low as 10%