Mix your own octane booster, here's some recipes. MOST octane boosters are little more than snake
oil, with missleading advertisements, choose wisely. We were running Aviation gas for the Formula Ford race cars when the track was open. Jet sizes were increased to avoid a potential lean condition. Toulene, inhaled, through the skin, on your clothes for instance, can cause brain damage, just thought I'd mention that...
http://www.gnttype.org/techarea/misc/octanebooster.html