Just wondering, a lot of the books I have talk about max compression you can run on the street with pump petrol. The thing is that the pump petrol they were talking about was relatively low (91 octane). These days in my area (australia) we can get 98 octane fuel....so when they say dont run anything above 10:1....would I be safe running maybe something like 10.6:1 ??

You have the ability to supply the fuel to it.

THe octane rating is the anti knock index, higher octane fuel runs cooler therefore help alleviate detonation. Higher octane fuel in itself will not help anything unless you have the ability to supply this fuel to your motor.

Heres something that will help explain it as well

http://auto.howstuffworks.com/question90.htm

Very interesting read Zmefly, thank you for the link.