Between tank heaters (in heater hoses), lower radiator hose heaters and freeze-plug block heaters, I like the 500 W freeze-plug block heater the best for the stovebolt six. It puts the heat under the manifold and makes starting very easy under very cold conditions.
The 1200 W tank heater on my '65 283 got warm air going in the defroster fast but I like the block heater on the six. Besides, you can't put tank and lower radiator hose heaters on some engines because the convection currents would not be right and overheating could result.
A 250 W magnet type heater is good for keeping the oil or the starter warm. I use that on the pan holding the 3 gallons of oil on my Cummins in really cold weather.
1948 3/4-Ton 5-Window Flatbed Chevrolet 34 Years. Now with a '61 261, 848 head, Rochester Monojet carb, SM420 4-speed, 4.10 rear, dual reservoir MC, Bendix up front, 235/85R16 tires, 12-volt w/alternator, electric wipers and a modern radio in the glove box.
