To find this information, I recommend the following resources:
* The owner's manual for your specific 1984 G20 van: This is the most reliable source for vehicle information, including fuel tank capacity.
* Chevrolet's website: They may have archived information about older models.
* Online automotive databases: Websites like Edmunds, Kelley Blue Book, or Autotrader often provide detailed specifications for vehicles.
* Online forums or communities: Websites dedicated to Chevrolet G20 vans or classic car enthusiasts might have the information you need.
Good luck with your search!