>   The older T2 vans used the framerails I believe, a la Bug,
to dispense the heat to the front aka heater channels.

The earlier Type 2s used a central heat duct similar to
the aircooled Vanagons.  Their gas tanks were on top of
the frame, just forward of the engine, well above the
heat exchangers and the heat duct--and well placed to
make those vehicles wonderful in snow....

                                Richard A Jones
                                Boulder, Colorado