With this prop I think you will see around 10,500-11,000 in the air at full power and producing around 8-9 pounds of thrust
my numbers were static, on the grown.. if he is going to stick with an APC I still think he would be better off with an 18X5, the 18X5 should keep his engine up around 8800 Static, and that is were the guys have reported their Saito's 180s like to be, as well as my Magnum 180 did
Jim