Hi John
I think you are in Australia. (It's always helpful to include your location
in postings.)

A couple of suppliers in Australia a
VW Engine Cent http://www.vw-engines.com/main.htm
Aeropower: http://www.arach.net.au/~munks/AEmenu.htm
(certified VW-derivative aero engines - some very useful info here)

and don't forget Jabiru!

Regards
Phil Maley
Perth