Am I correct that I have to run a gas that has an octane level less than or equal to my compression ratio. For instance, If I have 9.1 compression, I'd have to run 93 octane gas. Am I correct?

I'm not sure if that's exactly how it works. In fact I think 9.1:1 or 9:1 around there works on 89, probably 87? I think the guy who sold me my engine rebuild kit said what I had put in (new pistons/cam) would probably be about 9.5:1, and if that's so, I run 87 just fine.

No it doesnt have to do with static compression it has to do with dynamic compression and timing. My 11-1 540 runs fine on 93. Not sure of your combo but it should be able to live on regular or plus

I run 92/93 in mine, doesn't like the other stuff, but it will run till you can get to the station, not that I run out of gas, well maybe once or twice, good ole AAA.

I'd say that anything around 10.25 and you need 93... Just an estimate.

Octane rating is the number of carbon to carbon bonds in a chain that makes up gasoline. increasing the oct. increases the point at which it burns (this is why lower octane fuels will detonate) At 9.1:1 89 is sufice 93 will be acceptable till the higher 12's:1 are reached.

See Organic Chemistry IS good for something

Also winter fuel has a lower burning point
and summer fuel has a higher burning point
(this is to help start and reduce overheating respectively)