The Evolution is going to fit in the cowl better than the K&B. As for horsepower rating, I'm not real sure. I do know that my OS 46 AX and 11 x 6 prop had no problem pulling a .46 sized Cessna through all the maneuvers. I'm assuming the Evolution will do the same on the Decathlon. It just won't do the unlimited verticals or go as fast as something like a 55 AX.

NorfolkSouthern