The 14017724 is a GM OEM elbow (often referred to as an extension) for the air injection diverter valve in the vehicle’s emissions control system, part of the A.I.R. (Air Injection Reactor) pump setup found in older carbureted engines. Based on available parts catalogs and diagrams, it is compatible with the following vehicles (likely limited to those with specific V8 engines requiring this emissions component, such as the 350 or 454 cubic inch variants):