Hi Mary,
Moving the mast to windward, say 4ft, does increase the righting moment. Say the mast and rig and sails weigh 100 pounds. In the center of the boat they generate 400ftlbs of righting moment. Move them 4ft to windward of center and they generate 800ftlbs of righting moment. The people righting moment on this boat would be something like 11ft X 325lbs = 3575ftlbs. Moving the mast to windward would increase the righting moment roughly 400 ftlbs out of about 4000ft lbs or 10%. This sounds a somewhat interesting until we look at the included angle between the mast and the windward shroud. It the mast is stepped 8ft away from the leeward hull on an 8.5ft wide boat, what is our windward shroud angle relative to the mast?? Ans. 1.4degrees. I don't think that is enough to hold the mast up, Mary.
Bill