> wondering why my 77 Westy has such poor heat inside.

Courtney:

I had a '76 non-Westy for years and it was cold.  I used
to tape up 1/2-2/3 of the rear air scoops to reduce air
flow into the engine compartment--something the VW dealer
suggested.  I'm not sure I'd do that anymore--and I don't
think it made much difference.

The heater duct under the bus was a corrugated plastic
tube with a flimsy plastic covered insulating blanket around
it.  I don't think it was very effective when new and
yours is now 30 years old.  I never thought the heat exchangers
were very effective, compared to the ones in my 911s, but
G Matthew Bulley wrote up how he insulated and improved the
heat output a few years ago.  Most of his pages are archived
at:
http://www.type2.com/library/heat/heat-soundproof.html

When passengers in the back of my '76 used to ask when it
would get warm back there, I'd reply "April!"   ;-)

Richard
Boulder