Cylinder head temps?
That depends on how and where the head temp is taken.
A heat gun IR will give a colder temp reading.
A spark plug gasket thermocouples will give the hottest riding.
A hot hot spark plug will put more heat through a spark plug gasket thermocouples.
If the cylinder temp is low and the head temp is high you can overheat the piston dome and seize.
Due to the cylinder not having enough thermal expansion to provide clearance for the more greatly expanding piston due to increased piston dome temperature.
This happens more with aluminum cylinders than cast iron due to its properties of greater thermal expansion.
Plus having a piston with a higher silica content will expand less with temperature thus reducing seizing.