DCR is highly over-rated as a diagnostic tool. The safest use is to estimate results on the same engine, not to compare engines.
The 165 gauge pressure is pretty useful, but the actual cylinder pressure with ignition changes very quickly based on the cam. A mild cam's pressure goes up much faster than a hot cam with the same DCR and will knock at a lower throttle opening.
Most engines "see" close to their static CR by 3000 RPM because the valve does not close fast enough to overcome intake charge inertia.
