First, your radiator is a non-pressurized system and, from the factory, was designed for water only. Back then, the tight-wad farmers didn't add antifreeze. If they did, it was alcohol-based, which had a low boiling point. During the cold winter in all places except California, the water was usually drained every night. Also, your gas tank sits very close to your engine. They didn't want the gas to vaporize because it was so close to the hot block.
A couple of weeks ago, I drove my Oliver 70 about 10 miles in 90° weather. (Google for a photo of an Oliver 70. From the factory, it had enclosed tin around the engine) Now gas is different than it was back in 1938 when it was built, but my tractor did experience vapor lock the final two miles of driving. Your 180° MIGHT work, unless your are plowing the back 40 in high temperatures.