I have a nine inch rear that is a 31 spline and posi. I would like to put this in a car I'm building. It bolts in fine but is an inch too wide on each side. I have been told that the axles shafts can be cut down on 31 spline axles. My ? is would they need to be cut down for only an inch or could I just let them sit in an inch farther. Also would there be enough of the spline left or would I need to get them resplined also?