A +/- 55 degree rudder movement is quite sharp, U know.. The comming Ohio hull from ThorDesign can move it's rudders +/- 35 degrees, enough to control the >70" model. R U sure U need more than that?
If it's a Q about rudder rod travel distance, you can change this by changing mechanism where the rods are connected to the rudders. (Have played with this myself)
Yours Sincerely, Robert Holsting, Denmark
1/81 SSBN Ohio Class scratch builder, more at www.robse.dk
"Never be afraid to try something new; remember that it was amateurs who build Noah's Ark, and professionals who build the Titanic"