Sounds like a 14x4W is the right thing to do then. No sense in asking the warranty to be void...

I'm gonna tach the ole' Saito tomorrow. I have no clue how hard it turns the prop, I've not tached since it was broken in. Due to a recent mishap with my plane, frozen fingers, and Terra Firma I have switched to my back up prop.[&o] I'll tach it on a Pro Zinger 14x4 and see what I get. When I hit up the LHS for another APC or two, I'll have to tach that one too.

My YS 91 FZ did 10,600 on an APC 16x4W and Wildcat 20/20. Now that was some pull on an 8 pound Su-Do-Khoi 60!