* The vehicle's original owner's manual: This is the most reliable source.
* A 1984 Chevrolet C10 brochure or specifications sheet: These often list weights for different configurations. You can find these online through various automotive history sites.
* A vehicle identification number (VIN) decoder: Websites and services exist that can decode a VIN to provide some specifications, possibly including curb weight, but this is not always guaranteed.
Without knowing the specific trim and options of the truck, it's impossible to give you a precise curb weight.