M81202 Actuator - Rudder Stop Parameters

The manual states that the rudder stops are to be reached before the cylinder reaches the end of either stroke. I am installing new stops but would like to know what the design minimum is for the M81202. An inch before the end of stroke or a 1/16 of an inch before end of stroke? I assume that some number exists that stops the cylinder before the ends and leaves us with a 60 degree sweep with a 11.5" tiller arm.

Thank you!