It is 28 spline unit but I have 31 spline units and eaton units and even true trac units being made.
I am even doing lower cost reconditioned unit for the guys that just need a driver posi instead of everything brand new. Tried to cover all the bases with as much money as I could hang out there for a small business guy.
I had a machine shop do the ring and drill the holes for the units .... As I always say let people do what they do good. I am not a machinist...lol
I am trying to supply these for way less than the SCU .... that is just too much money and these rears deserve to be back on the road...