It is kind of like polishing a turd. If you're gonna spend the $$ on 31 spline axles wait til you can also get a BB rear housing. I am in the same boat with the wifes 66. She just got an ARB for up front, but I refuse to waste the $$ on a 28 spline or a SB rear kit to get it set up. I hate to buy the same parts twice, especially the expensive ones.