questions on timing an engine

Disclaimer: I'm ultra-tired, so if I'm turned around on anything, someone will probably find it and steer you right.

If you're setting it to 35 degrees when it's fully advanced (3500 or whatever it ends up being due to springs and such), the initial doesn't matter. The difference between initial and total is determined by movement of the mechanical advance mechanism.

Mechanical advance works as follows: The springs and weights work together to determine the rate (what RPM it's done advancing) and amount (length of the slots).

Example: If you want to set initial advance at (let's say) 15 degrees with a total of 35 degrees, the slots would need to be modified (to 0.405" (I think)) to give 20 degrees of mechanical advance. The total is all in the length of those slots.

Note: Everything above is in crankshaft degrees. Divide by two for distributor degrees.

It seems kinda strange until you pull it apart, see how it all works together and have that "Aha!" moment. It'll pop into focus soon.