I have the D30 up front. My knowledge of the various differential combinations and what works with what is limited. When my mechanic went through these 5 years ago he talked me out of a detroit locker for the rear which was probably a good thing. A trutrac 4.1 went into the rear and the front was left “open”. Not sure if it was because a trutrac couldn’t be put into the D30, the original LS was hard to cone by, or I thought I was going to easily find a D44 for the front. Pics of what I have now.