I am curious to know how your additive works for you. I have a 455, with #48 heads, and using California 91, it pings and diesels. I have been running 100 octane for some time, but I drive the car so much, the cost is unbearable. I have purchased
https://boostane.com., which I plane to mix with 91 pump gas. The savings is marginal though as it is $20+ a bottle.