Anyone know how many splines on 6W1Z-4234-B axle shafts, and how they differ from 6W1Z-4234-A? If they are 31 spline, then are the lengths or bearings different?

6W1Z-4234-A 31-spline axle (manufactured from 12/04/2004) (replaces 5W1Z-4234-A) (2005-2010)

6W1Z-4234-B lincoln towncar limousine limited slip axle (replaces 3W1Z-4234-GA & 3W1Z-4234-LA & 4W1Z-4234-A) (2003-2010)