Prop Pitch question...

[revi]

thank you for your details, I am no mechanic (ie; dont even know how a transmission works) and I am finding the concept a little ambiguous...
This is how I see it...can you please correct my thinking where need be...
If I set the prop pitch to 66% (in a plane with a constant speed prop) this will:
adjust the pitch of the blades to have less of an angle therefore making the prop spin easier and faster...increasing the RPM of the engine??
Another thing , you say "when diving use 60-80% prop pitch, and also to throttle back".
Does this mean that the increasing air speed (which your plane encounters during a dive) can and will increase the speed of your planes prop, which is what causes over revving?
Therefore as a precaution you should throttle off and change blade pitch?