To find the gas tank size for a *specific* 1976 four-wheel-drive truck, you'd need to:
* Identify the make and model: This is crucial. Knowing it's a Ford, Chevy, or Dodge is a good start, but the specific model (e.g., F-250, K10) is essential.
* Check the owner's manual: If you have the original owner's manual, it will specify the fuel tank capacity.
* Look at the truck's data plate (or sticker): This plate, often found inside the driver's side door jamb or under the hood, may list the fuel tank capacity.
* Consult online resources: Websites specializing in vehicle specifications (like Edmunds or Kelley Blue Book) may have the information, although you'll need the exact make, model, and possibly trim level.
* Contact a classic truck parts supplier: They often have detailed information about specific models.
Without knowing the exact make and model of the truck, it's impossible to give a precise answer. Gas tank sizes in those years typically ranged from around 15-30 gallons, but that's a very broad range.