Again, somewhere on the vehicle I don't know too much about. From research I know I should upgrade to 31 spline's and either strange or moser are about the best. The thing I don't know is about the eaton or auburn t-loc's. Is this part to lock both tires up at the same time for drag use/better traction? Also, I see them advertised as 28 or 31 auburn/eaton. I take it if I get 31 spline's I need to get 31 auburn/eaton, correct? And where is the best place to purchase these and what combo is best in your opinions? Thanks.