The 3J driveline is a plated differential which offers far superior traction over a traditional ATB diff. With the added performance comes a cost, and this is that a plated differential is unfortunately not a fit and forget item. There are servicing intervals on these and therefore only recommended for track biased cars.
Custom settings are available to tailor the diff to your needs. There is roughly a 1 week lead time on custom items.
Track - 40/90 - pre load 75-85 lbs/ft