In New Zealand, 100ll and race gas are one and the same thing. I fly a Remos microlight with a Rotax engine that happily runs on both avgas and mogas but you have to shorten the oil changes with the avgas as a grey sludge builds up in the oil reservoir.
Yes, you have a plane. When I talked about high octane race, I was talking about usual high octane petrol used for racing cars and motorcycles. Those are usually unleaded. With your plane, you do not have a catalytic converter, hence you can (somewhat) run avgas 100LL which is leaded, without too many ill effects. However, in a (modern) race car, even without a catalytic converter, sludge in the oil reservoir and therefore in other places is not really something you want.
