>   diesels were only available for a
> couple of years in vanagons.
>
But they were available for a lot of years in other VWs, and parts seem
to be fairly plentiful if you look around a little. Except (I think)
for the oil pan, engine mounts, and the "throttle" arm on the fuel pump
(in the vanagon they are bent down instead of sticking up, but that may
or may not be a problem in your application and can be bent down
anyway) I think most everything is the same. You should get a diesel
fuel filter because it has the means of draining the water out of the
bottom now and then. I think the aircooled transmission final ratio
works well with the diesel, but check on the list.
Jim