I never have tried a 13x5 prop on my YS 63, APC or Zinger. I have never tried to push my YS 63 over 11,000. I'm generally happy with anything over 10,000 static, then I know it will be over 11,000 in the air.

There is a world of difference between the razor sharp APC and the very ineffficient, thick-edged, blunt-ended stock Zinger. When I use a Zinger, I re-shape the tips to somewhat resemble the APC (more like a Zinger Pro), and sand down the thickness to get something closer to a feather edge on the tips and TE of the prop. I normally alternate between APC and Zinger depending on whether I want more weight in the nose or less. More weight with APC and TruTurn spinner (heavy backplate), less weight with wood prop & plastic spinner. I have never compared rpm directly between APC and Zinger of same nominal dia-pitch, but I do know I get a few hundred more rpm out of a Zinger between stock and modified.