A Chevrolet gas tank is not thought about much by the owner of a vehicle until there is a problem or it leaks. It is true that Chevrolet models only have metal gas tanks and they cannot be repaired easily. The process would require the tank being removed, flushed of all combustible fluids, and allowed to dry before the hole can be welded. Because of this and the danger of explosion it could cause, most welders will not make repairs to this auto part. For safety reasons the Chevrolet gas tanks are attached to the bottom of the trunk floor behind the rear wheels. On pickup trucks, they are located behind the cab under the bed. They are usually held in place with two straps. This prevents the gas tank from entering the passenger compartment if a rear-end collision occurs like the famous Ford Pinto had back in the 1970's. Before the tank can be removed from the vehicle, both straps on your Chevrolet have to be loosened. But, the tank has to be supported so the fuel lines and sending unit wire can be detached. This process has to be conducted carefully and ideally with little to no fuel in the tank so it will be easier to handle. Also remember fuel is flammable, so no smoking should occur near the vehicle during this repair job. The only reason for a fuel tank would have to be replaced on your Chevrolet is because it is leaking fuel. This can occur if there was a puncture of the tank or rust has developed on one of the older cars due to all the years it was exposed to salty condition from the roads during the winter.