I sure tried a lot of different props on a Saito 56. The only rule I discoved is that it's entirely dependent on the plane/engine combination. I built a plane and went through probably 30 props before I tried this 12x4 eather 3 blade UC prop. This particular one really made the plane come alive with the Saito 56. I transferred the entire setup; engine, prop and tank to the next version of the same design. Only a very few changes in the the airframe and of comparable weights. It flew OK with that prop, but nothing to write home about. Went through another 30 2 and 3 blade props from 11" to 13.5 inches. and finally settled on an 11.5 x 4.25 three blade Eather. It was cut down from a 14x4 so had really wide blades. Worked very well.