<VV> Pitman Shaft adjustments change the "turn ratio" ?

[Charles Lee]

I'm being overly 'delicate' not wanting to break anything in the process, so 
thanks ...

Here's my latest updated pictorial summary of the process :
http://www.yourbuyersinn.com/Cars/Corvair/1965CorvairSteeringBoxExplodedView.jpg

Right now, I'm trying to figure out what exactly the "Lash Adjustment Screw" 
actually adjusts ? (#13 in the figure above)

I don't seem to get enough turning of the Pitman Shaft but do not see how 
either the #1 or the #13 adjustment would change the "turn ratio" ?

Charlie