I have 31 spline axels with traction loc 9" and am quite pleased.
May I suggest you make sure the "pig" is setup correctly with the ring and pinion giving a good pattern.
If you are using the Torino bearings, you will need to make sure the retainer does NOT crush the seal into the axel, but seals the housing.
I went through three sets of seals before I stopped the leaks, I pressed the bearings myself the last time.
Also, the 31 splines are much larger and weigh more...if weight is a concern.
Hope this helps.
