Battery is run down or on it's way out.
5W30 weight in the cold months. 10W30 in the hot months. If you use HEAVEIER weight it will BURN the valve train up / CAM and LIFTERS.
A sticky brake caliper could do that.
210-220
Did u check your enigine cooling fan?
the system is probably out of coolant.
There should be one female plug-in and one separate hot wire that is hot anytime the battery is hooked up.
There are a number of places one can find a 1956 Chevy truck for sale including Autotrader, Classic Trucks, Custom Classic Trucks, Old Ride and Blue Ridge Hot Rods.
Maybe your cooling system needs to be flushed out.
Could be a bad actuator switch which operates the door flap, therefore allowing air to constantly pass across the heater core, hot into the cab. The actuator is located behind the blower motor, which is under the glovebox.
There is a leak in the rear lines running to the back.
5W30 weight in the winter months and 10W30 in the hot months.
Either a faulty thermostat or you have a low coolant level.