Pat:

Consistent 70mph may be asking too much, and 65 on a windy day is pushing it
in my similar 81 Westy. 60 is where my van likes to cruise, FWIW.  I
recently did a tune-up (with the able guidance of my brother, Tony)
including plugs, points, rotor, cap and set dwell/timimg per the specs in
the Haynes manual.  My van all of a sudden has a lot of pep, so maybe the
timimg adjustment did it?

The vanagon is about 500lbs heavier than the bus, so with the same engine,
it's working harder.  Slow down and take in the view!  I'm glad to hear you
are enjoying it.

Melissa Mourkas
81 Westy