Think I've just found someone who doesn't reach ICAO 4. Danny, you wern't downroute and bored yesterday at 1715 hrs by any chance?
Russbell 1, all the aviation approved parts suppliers for a Continental 0-200 Aero-engine will require similar levels of payment for aviation approved parts for your aviation engine.
May I suggest you find a VolksWagon Beetle engine for your needs. You may find that parts for this are more within your means.
camlobe