This product is a set of 8 NOS (new old stock) GM 3946077 exhaust valves designed for use in 1969-1971 BBC Chevy engines. Manufactured by General Motors in the United States, these steel valves feature a chrome-plated stem for durability and corrosion resistance. These vintage parts are OEM (original equipment manufacturer) components, making them a great choice for restoring or upgrading classic Chevrolet vehicles.