i agree the temperature sender or probe needs to be after the radiator, and preferably in the water jacket around the cylinders.
a good place [in my opinion] would be where the block drain plug is located.
i am also a guy that likes to see the engine temperature at, or around, 195-215 or so. this is with a 16lb or higher [20-22lb dirt track radiator cap] radiator cap, and a 35-50% mix of water and coolant.
i think the extra heat produces a tick more oomph from the engine, as well as making sure all acids and moisture's are boiled out of the block internals.
remember, this is just my [old man] opinion.
your mileage will vary.