Could you run 87octane gas in a Chevy 350 with 12 to 1 Compression Ratio?

Chances are that no matter how far you retard the timing to avoid pinging, it would still ping at part-throttle. Also, it would probably run-on when you tried to shut it off. My opinion is no, you can't run 87 octane fuel in a 12 to 1 engine.

Another Opinion:

The above seems about right to me. 12 to 1 is up there for a 350, pretty much into the racing engine territory. You'll probably need to find some high octane fuel to operate at that compression ratio, and if it's an EFI engine, you'll need to find a way to get the computer to work with you.

Also, check with the emissions requirements in your state. Oxides of nitrogen will be off the chart with 12 to 1.