fixed a few problems

[twhrider2]

Not sure if they come in different diameters or not but the one I have is 151/4 I'm pretty sure. The 17p is 151/2.

[spareparts]

they generally adjust the diameter from pitch to pitch to try and even out the rpm drop from each pitch number. If you want a little more rpm, have your prop repair shop look at it. They can usually tweak another 200 rpm out of them