Originally Posted by Cab_Burge
To make the most HP you can on your motor you don't want to use the highest octane gas out there, it is a waste of money and fuel.
I would try either C10 or C11 if you insist on running leaded race fuel.
The least octane fuel you can run in that motor without detonation will make the most power and make the car run the fastest scope
I've been there done that with my old M.W. 1963 Plymouth stocker shruggy


I also race a 1968 Barracuda in SS/AH, so it is easier to carry just one brand of fuel. I have tried VP C12 and there was no difference.