EFI and C/R

I was looking through CI's information on the AL head. Planning out my EFI system. I noticed a huge performance gain going to EFI, but thought it odd since most side by side comparisons on V-8s (where a magazine did a swap on the same engine) didn't change peak numbers by a significant margin.

But I noticed Mike used an estimate C/R of 10.5 for the calc. Can an AL head, with EFI run a higher CR than what I'm running with my cast iron Oz250 head and carb?

I know AL can generally handle a higher CR due to the thermal conductivity of AL. Does EFI buy me a few more points on pump gas (even with premium)?

I'm not sure if this is entirely correct, but the way it was explained to me was since fuel is jetted in through the carb at the beginning of the manifold the air intake temps don't change much. But with fuel injection it is sprayed into the runner from the fuel injector in the runners which is closer to the head and cools the intake charge temp more before going in, giving you that ability for a slightly higher C/R's. Obviously if this is true then the GM throttle body injectors wouldn't have this same affect. Plus it follows along with the laws of thermo dynamics and fluid dispertion theory book i have.

Of course I'm no expert, but this is the kind of stuff i love looking into.

Just switching to an aluminum head allows a point more compression just from the heat transfer.

The reason some engine management can run high CR is because you can monitor and adjust fuel and spark to changing conditions. The systems can dial back on timing, add more or less fuel, even control throttle and traction in order to prevent detonation.

There are some injection strategies that take advantage of evaporative charge cooling as well.