I have not seen it on a van. But there are conversion kits for the Mopar 8.25 and 9.25 rear axle for trucks and for old A and B-body cars. I sent a message about one on Summit a while back LINK!!!
and was politely told no it would not work on a van. But I really don't believe that. In my mind everything would work except the e-brake cable, which would be made for the car or truck.
Also for the 8.25 axle if you google you can find parts lists to get factory parts off some of the later model Jeeps that are becoming more common in the junkyards. There are a lot of off road guys who do it.
This is also on my long list of van upgrades I'd like to do. Just have had to prioritize other things.