Rick,
That engine looks like it has puhlenty of elbow room in there. The three bladed prop on mine is a Master Airscrew 1570; I assume that means it is a 15x7? Whatever, he will not be attending the next flight with me as I stand out next the windsock...ha. I am installing an APC 16x8 two blade as per Saito and see how she likes that. Also, I am running Cool Power blend with 15% Nitro and 18% oil. Finished all the covering last night, and got started on the rudder servo mount re-do. I am using Sullivan blue and yellow rods for this, threading the blue jacket through the fuselage was not all that fun really. Almost there.......