It has been discussed in the archives in the past.
As Tom mentioned, pin 3 is the recommended starting point.
The difference between each pin # is quite a bit so most people end up somewhere in between.
Since a smooth running engine requires blades to be pitched within .1 degrees of each other, you have to measure it. Neither the old style or new style hub gets the blade pitch relationship accurate enough.
Any opinions expressed in this message are my own and not necessarily those of my employer.
RV-6A (aka "Junkyard Special ")