You can run 10.5:1 on pump gas without issues if you plan your entire engine build.

Detonation occurs when excessive heat and/or pressure builds up in a combustion chamber causing the air/fuel mixture to “auto-ignite.” This produces multiple flame fronts within the combustion chamber instead of one hot burst. When these multiple flames collide, they do so with explosive force that produces a sudden rise in cylinder pressure accompanied by a sharp metallic pinging or knocking noise. This is "head" independent - however; some combustion chambers (such as those in the Vortec heads) are better suited to complete combustion. Mild or occasional detonation can occur in almost any engine and usually causes no harm however; prolonged or heavy detonation can cause a lot of damage.

The octane rating of a given grade of gasoline is a measure of its detonation resistance. The higher the octane number, the better able the fuel is to resist detonation. Most engines with static compression in the 9-9.5:1 will run fine on regular grade 87 octane fuel. Engines with high compression ratios, such as your projected 10.5:1, require at least 89 (or higher) octane fuel. If switching to a higher octane fuel fails to eliminate a persistent detonation problem, it probably means something else is amiss. Anything that increases normal combustion temperatures or pressures, leans out the air/fuel mixture, or causes the engine to run hotter than normal can cause detonation.

A static compression ratio of 9:1 is typically the recommended limit for most naturally aspirated street engines. Compression ratios over 10.5:1 may create a detonation problem even with 93 octane premium gasoline. That said, BMW, Volkswagen and Toyota all sell cars with compression ratios over 10.5:1 and they run fine on most pump gas (BMW V8 in their “M’ Series is 12.5:1). I say most because there are some states that mandate high percent Ethanol during certain month (usually winter) and such reduces the octane and an octane booster is recommended – even with premium fuel.
Use the coolest plugs you can. The wrong heat range plug can cause detonation as well as pre-ignition. If the insulators around the electrodes on your plugs appear yellowish or blistered, they may be too hot for the application. Use the next range colder spark plug. This can happen real quickly – so stay on top of the plugs.

Make sure to have a big enough radiator. Lots of cooling is a good thing with higher compression ratios. Get a good water pump and lots of fan.

Richer fuel mixtures are less likely to experience detonation. Lean can be very unforgiving. Vacuum leaks at, intake manifold gaskets, or carburetor gaskets can lean out the fuel mixture. If the fuel mixture becomes too lean, misfire typically occurs – especially under load.

Others will certainly chime in - this could be a great thread.

Regards,
Glenn