leaded or unleaded fuel

I mix 3 gal of 93 pump gas to 2 gal 110 race gas. I do this b/c I really don't need the oct level of race gas, but with the ethanol in pump gas I had issues with pure pump gas boiling in the carb esp on hot days. I do this in 3 of my cars without an issue. They all run very consistent. The compression rations are only 10:1 to 11:1 in all 3 cars though.