Here is the real industry info on the "PowerTrax" unit you are talking about.

At SEMA 2014, I approached the supplier to produce an 8.75" Mopar variant based on their Ford 9" helical gear differential.

After receiving the prototype in July 2015 and making a few revisions, I contracted them to supply me the unit.

When my production run arrived in April 2018, the supplier sold me 300 of the 350 pieces I ordered. The remaining 50 were distributed to several re-sellers under the PowerTrax name. None are currently in stock from the supplier.

I ordered another run in October 2018. I made a few changes so my unit will not be confused with the other version now being sold. I'm still waiting for my new order to be completed.