Phil
That extra inch is a lot for a starting point. The standard is to add or subtract 1/8" for every inch you are away from 5'8", starting at 13 1/2". That would put me, at 6'4", looking at 14 1/2" as a starting point. But I have narrow, very square shoulders and actually need a stock only about 13 3/4" depending upon application.
Also, cast will affect the apparent length of a stock and change your LOP as a result. Cast-off decreases LOP while cast-on increases it. Drop will also affect LOP needs...
art
