Standing Rigging Tensioning

Hello Everyone,

Preliminary Info:
I have decided to go ahead and replace all of the standing rigging before the circumnavigation.

I was just about to have the old ones duplicated exactly when I learned that this could end up being a very expensive mistake due to the fact that if the old cables had stretched, the new ones would be too long.

So now, I'm going to hoist the rig and tension the wires to the correct amount.  Mark the place where the turnbuckles are exactly when the rig is at the right tension.  And then release enough tension on the turnbuckles to unfasten the rigging wires.  And then set the turnbuckles back to their "proper tension length." 

Only now do I know that I have the proper length for each standing rigging wire. 

My Questions:
What is the proper tension for the standing rigging?  And how do you know when you have it set?
(I have 3/16" cable for both for and aft stays and upper shrouds and 5/32" cable for the 4 lower shrouds)

What is the "ideal" position of the turnbuckle when this tension is set?

Thanks much for any advice,

This is one of the last big projects on the boat as I near the end of the re-fit.

Brian

ps -- reading "lone voyager" about Howard Blackburn right now........can't put it down......great book.