Gus-
I checked my airplane logbook, and verified that my prop is a metal Sensenich 76 x 60. With that prop, I run acro at full throttle.I am trying to learn to fly the figures in such a way that I will not have to pull back the throttle at all (except for spins, of course!). I'm told that it will be hard to get good figures, especially round loops and straight 45 downlines, if I pull the throttle back.
Like you said, controlling airspeed controls rpm. For example, in a hammerhead I can (try to) use the timing and aggressiveness of the pull after the downline to keep the airspeed where I need it for the next figure.
Tom P.