Yah, those recommendations are odd. Towers site shows an 11x6 or 11x7 for the .46-LA but that's too much in my opinion. Perhaps I am wrong. I even know people who run highr pitch 9" props on the .46-LA Then Tower shows a 10x6 for breaking in a .46-AX and that's the engine that should get the 11" prop. Maybe there was a mix-up or something.