The early Z series Datsuns (2 seat coupe') with the 1 3/4" SU type carb
are heated. There's a cavity near the base through which coolant runs.
There's a special inline thermostat to keep the heat at an even
Most modern cars run hot water through the intake manifold to
stabilize intake air temperature. Slightly older carbureted cars
often run hot water through a thermal block around the base of the
carburetor to stabilize the carburetor temperature.