I can get the Sunoco (leaded) Racing Fuel right around the corner from where I live, but at $6.50/gal, I settle for the 93 octane (unleaded) variety. My tank holds twenty-eight (28) gallons, so that would be an expensive fillup.
About twenty (20) years ago, I had my cylinder head rebuilt with hardened valve seats and umbrella-type stem seals. Even though I have about as complicated a fuel delivery system as you can imagine (3 X Weber 45 DCOE) I don't have any trouble with popularly available gasoline.