leaded or unleaded fuel

so a friend and I were at the track this weekend and started a conversation about fuel. Currently he mixes 3 gallons 91 unleaded pump to 2 gallons 110 race leaded. I asked him why he does that he said the high compression. My question to you all is with the modern technology (hardened seats) cou you just use a unleaded 110 race fuel ? Do they even make it? What does mixing the 2 have to do with the high compression. His motor is 12:1. My big block is 14.34:1 and I use 110 leaded. Can I too, if they make it just use 110 unleaded race fuel?