They were regarded as noisy for a Statesman, in a van it'd make no difference especially with the tailgate up.
Other option is a 2.6:1. Or get mounts welded on a VN- VSIII 3.08 diff and get the stud pattern changed to HQ. Requires a tailshaft mod too but will give you rear discs. HZ drums may fit this diff too after a stud pattern change, can't recall exactly.