Salvo, I've added those questions to the list of what to test out tomorrow :).
Anybody else have suggestions for what to investigate?
Thanks, smkettner, for the springs alternative.
I have been reading, reading, reading on the van forums, and taking copious notes. A few days ago I knew nothing about suspensions, but now I have half a clue.
I will go back under the van in a bit and look with smarter eyes. It has become clear that I could easily spend $1000 on suspension upgrades. I think I will need you folks' help prioritizing.