Thanks for the tips, fellows.  I didn't really find and follow the Bently procedure on filling and 'burping' the cooling system.  I suppose I thought I was 'smarter than a radiator'  and so, proved I am not by skipping the "Instructions"...
  Anyhow, I am hoping, and the behavior I've been seeing from the Van leads me to believe there IS  some air in the system, that a meticulous purging of the air will straighten this problem out.
  Don Hanson