Did you not read post 11?

OR

Are you asking what the advantages and disadvantages of how far the leading edge of the rudder should be from the prop? If this is your question, normally the rudderwould bebetween 1/8" to 1/2" far from the prop shaft or bullet nut depending on manufacturer. Asfor advantages and disadvantages in turning ability none, as for easy removal of flex shaft and prop, just loosen the rudder bolts and swing to one side to pull out the flex shaft should you need to either replace a prop or shaft for that matter.