I'm surprised no one has mentioned this yet. If the head gasket is blown, that can heat up the water real fast. All it would take is one crack in the gasket near an exhaust valve, and the hot exhaust could be super heating the water in no time.
I doubt the fan is the problem. My '48 has an electric fan about that size, and the only time it gets above 180 is when it's really hot and I've got the air conditioning running full blast (in Texas 100+ heat). That will push it to 190 or even 200. And I don't have a shroud. The fan is blowing through the condenser and the radiator.
This may sound stupid, but make sure that fan is sucking air through the radiator, not blowing it through the radiator. Since you've got it mounted on the inside of the radiator, you want to pull cool air from the grill, not push hot air from the engine through it. If it is, mount it on the outside of the radiator so it blows the cold air through the radiator.
Pulling the head on the 235 is not very difficult. I would do that before you spend any more money on parts.
coolant was tested for head gasket/block leak. no sign of hc in the coolant. i tested it 3 times. Fans are going the correct direction. might have to pull head and examine.
