To find out if *your* truck has one, you should:
* Check the owner's manual: This is the best place to start. It should list the options included with your specific vehicle.
* Look for a cord: The block heater cord usually protrudes from the engine block near the front of the engine, often near the oil filter. It'll have a plug on the end.
* Inspect the engine block: You might see a threaded fitting where the heater element would screw in. If it's missing, it likely wasn't installed at the factory.
If you can't find any evidence of a block heater, it's possible to have one installed by a mechanic, though it's usually more costly than ordering it as a factory option.