Mine did that until I added a fan shroud, now it's 180-190. At 210 it was crabby about re-starting. My '68 Charger R/T always ran too warm for my liking, and it was stock. Factory gauge.
The more pressure (radiator cap) you can put the system under, the higher the boiling point. You do not want the coolant to boil. 16PSI should prevent that.
Not sure what you're running for a cooling system, but I'd look at improving it. Venting the underhood heat (if you can) helps, but as far as I'm concerned you can't have too much radiator, fan & etc for a 440. Most of my 383s didn't run as hot as my 440s.