Gonna be running 100-110 octane race fuel my question is should it be leaded or unleaded is there a difference and also does oxygenated vs non oxygenated matter?
100 octane leaded has the same detonation protection as 100 octane unleaded. 110 octane leaded has the same detonation protection as 110 octane unleaded. The octane number is the fuels rating to resist detonation. The leaded fuel is usually cheaper for the same octane than unleaded.
Leaded fuel is preferred in four-strokes to help provide high temperature valve seat lubrication. It really does not matter which fuel you use in a two-stroke as long as the octane rating is high enough for your engine build.
Oxygenated fuels require richer jetting and have the potential for slightly more power.
Oxygenated fuels hurt rubber and plastic more rapidly.
Osygenated fuels create more health related issues.