The only to measure engine temp is when its at full throttle. Landing and usingan IR gun is a reference but no way accuret.
You need a data logger to get true inflight temps.
On a test stand with the IR temp reader only 1/2" from the spark plug boss, 320-360 is normal after 2 min WOT.
Our engines run a lot hotter than we think, BUT this is where they are designed to run.