Evaporating Fuel in Carter 4-Barrel Carb?

Just a ironic note.. A few months after I fought and conquered all of the issues related to todays grocery store fuels, I found where the real 92 octane gasoline is sold. Since that day, I go that distance and pay that price. Curb idle rpm went up a little but I refuse to change a thing. It'll run on either or, so I could leave town and fill up anywhere ( short of E85. I haven't tried that ).