One thing I noticed with the Warp taper tip is that the airfoils in the tapered section are not really very precise. (They're hand ground.) I therefore started measuring pitch at the 75% point to get the blades more even. (And no, I can't tell you off the top of my head what I'm running for my 100hp IV. My guess as to your pitch is 11.5 - 12 degrees at the tip.)