e85
If you are running full advance and 93 octane works, it would be a waste to go to E85. 30% more fuel. If you need higher octane to stay at full advance without pinging, it's a great way to go. Bigger jets, drill out metering rods, possible bleeders. It's 105 octane from the spout at $3.20 a gallon today. I just filled up with 9 gallons of 110 octane race gas at $7.99 a gallon. I have spent over $500 in race gas in 2 1/2 weeks. Guess what my next upgrade is? E85 here I come!