To find the fuel tank size for your *specific* 1977 Dodge motorhome, you'll need to:
* Identify the manufacturer: Look for markings on the motorhome itself.
* Identify the model: This will be on a sticker or plate somewhere on the motorhome.
* Consult a manual: The owner's manual (if you have it) will specify the fuel tank capacity.
* Check the fuel tank: The tank itself may have markings indicating its capacity.
* Search online: Search using the manufacturer and model, adding "fuel tank capacity" to your search terms. Sites like RV forums or parts websites might have the information.
Without knowing the manufacturer and model, it's impossible to give you a definitive answer.