why dont u use a j30 inside and an open diff housing with ring gear.

Summary:
J30 vlsd unit: axle shafts.
Open diff housing: ring gear, pinion, shims/spacers, and races.

It works if u use axles shaft from (j30) and open diff 4.08 ring gear and housing only.

Things not to do: use j30 ring gear on open diff housing.