Update time!
I did two things, and they helped a lot, but they may not be the whole solution.
1. Put more air in the tires. When I bought my BFG K/Os, I asked the shop to put in 60-65. But they said no, no, you don't want that and put in 42. Since they are an independent local shop with many years experience (not some 19 year old at TiresRus) I figured they knew. And you all probably figured _I_ knew! But 60 front and 65 rear helped a lot. Should I try more? The tires are rated for 80.
2. Got new, custom leaf springs. I now have 5 leaves instead of 3, and a bit of a curve instead of flat!
On the freeway, my friend who drove the van to and from the shop (an hour each way) says it is far better, though it now seems a bit floppy in the front, instead of the rear. He says the shocks are fantastic, now that they have some springs to work with. Me, I still cannot drive due to hand injury, so I have to go by his reports.
Parked, it is now as stable with zero jacks as it was before with one. If I nod my head while lying on the bed, I can feel the van rock gently.
So, where do I go from here? Take it to another shop for the front end floppiness? The spring shop only does leaf springs. Or drive it till the next chance for non-emergency repairs, 1000 miles, a couple months from now? (I'll be staying in an expensive area in the meantime... although they probably have cheaper shops I don't know about.)
