11-1 is right at the cut off for pump gas, I have run pump gas in a 11-1 motor brielfy but I wouldnt advise it.
What I did most of the time was use a mixture of race gas and pump gas.
And no......
Them octane boosters u get at your local parts house do nothing >pure snake oil :wink:
Now if live close to a small airport or a crop duster airport you might be able to get your hands on some av gas.
Goodluck with that pontiac>Cp