Steve, my experience with the 14 bolt has been spider gears on the 10.5" and various Gov-Loc issues on the 9.5 semi-floats. In either case, the broken pieces are not helpful, especially for the ring and pinion.
However based on your width issue, it sounds like you may be headed 14 bolt. I would recommend that if you have the Gov-Loc, keep the fluid changed often to prevent the fly-weights from gumming up.
Scott
