The actual measurement for adjuster protrusion (taking into account the rockers have the factory oil hole timing) is 9/32" +/- .020 and the more agressive the lobe the more important this is.
Pushrod length does NOT affect rocker arm geometry per se, as the only thing that controls geometry on a shaft is the relationship of the valve to the height of the stand, and the rocker itself. Lift factors in, but en talking about correcting geometry, you either raise or lower the shaft, or make the valve longer or shorter. The push rod length just affects how far out the adjuster is...