I recently got a real good deal on a used Powertrax No-slip to upgrade my Trac-loc. Part number 92-0688-3107 for 31 spline axles and open carrier. As I understand it this will not fit in a trac-loc carrier. I have an open carrier from a Ranger but it was for 28 spline axles. Is there a difference in the cases from 28 to 31 spline? I tried to contact Richmond Gear, but got no answer. I think I should still be able to use it since the Powertrax will replace the spider gears. Can I use this carrier or do I need to find a 31spline unit?