Get 5 gallons of sonoco 110 and 5 gallons of 91-93 whatever is high test. That will get you through your dyno session. 11.6:1 with 260@050 on intake and aluminum heads doesn’t need some crazy high octane number. Start rich with low timing and 110 and keep inching up on the tune up and adding pump gas to the mix. You’ll find your safe tune up and octane level. Then you get to put it in the car and do it all over again.
