When they were brand new I am sure it stayed cool. I own a 1936 Chevy Master Coupe and live in Phoenix AZ and in the summer when it is 100-118 the car will heat up to 210 if I am not moving and hitting a lot of stop lights. The car was restored about 20 years ago so I was considering flushing the block. Wanted to have radiator flushed but not sure I want to go through all the hassle of removing it. I will probably swap the 180 for a 160 thermostat to see if that helps.
Jeff, Save your money. The 160 thermostat will not help with overheating once the engine reaches near operating temperature. Flushing and cleaning out the coolant passages and radiator will help with the heat transfer resulting in possible lower coolant temperature.