Agree with Dayclona... get a "reliable" gauge to validate/understand/interpret what the dash gauge is telling you. A $10-15 parts store gauge will do it. See what the backup gauge tells you vs dash gauge and interpret accordingly.

On my setup, I run on the bottom line of the operating range while rolling on the dash gauge. Seems low. Backup gauge tells me it is right around stat temp of 180. All is well with the cooling system and engine. The (rebuilt) dash gauge + new sender just reads a bit low.