This is just off the top of my head...
I know that an Astro van was constructed essentially as half a unibody- it had the front half of a B-body frame with I think the same front suspension design (I may be wrong somewhat, possibly different parts mixed into it over the years, I know they used the heavier duty bolt patten, ball joints, etc.) that ran halfway down the undercarriage and stopped. The back is fiberglass leaf springs connected to the body shell with a live axle.
In '90 and later the Chevy Astro and GMC Safari vans were available with AWD as an option. I do know this system used torsion bars...anyone think there's a way it could be adapted to a B-body? LOL
You occasionally see lifted AWD Astros, so I don't know if this system is more geared on road or off road use, full-time/part-time, etc...