71 340 Compression Test

The numbers by themselves can be very misleading. But if you throw in the ICA,Or have the cam specs, and displacement, then it is possible to back calculate the Scr, from the Dcr and cylinder pressure. It is not exact. But it will usually ballpark it pretty close.
Your numbers would be on the high side for iron heads and pumpgas, but still have some headroom with aluminum.

What this means is that it is very possible to have high cylinder pressure with a low compression ratio and a small,short-duration cam, that HAS to run premium.
It also means that you can have a high compression engine with a big,long-duration cam that runs on 87E10.
High cylinder pressures are desirable at low operating rpms (like DDs), cuz the engine will make good torque, off the line, and stands a chance at making some decent mpgs.But the pressure has to stay within the limits of the intended fuel to suppress detonation. If you exceed the limit, then you have to pull out timing. And in most cases the engine will lose power faster when pulling timing than if the pressure hadda been a little lower. So for DDs and Streeters,it is usually wiser to stay on the lower side of the pressure limit. Weekend warriors can walk the line, and racecars can find fuel for nearly any reasonable pressure numbers.
Almost nothing sucks as bad as a LC engine that won't take throttle, even on hi-test, unless it is a hi-perf street engine that needs to have the timing pulled out of it, cuz hi-test just isn't hi enough..