I have a brand new in the box Eaton Posi for GM 7 5/8 stock rear end with 3.23+ ratio gears and 28 spline axles for sale. P/N: 19599-010.
I'm asking $475.00 and I'll pay the shipping to the lower 48 states.
I also have a shim kit that I'll throw in with the diff. (Note it does not include the clutches as they were used to rebuild a previous Eaton Diff)