G&N Aviation, Inc. of Griffith, Indiana was founded in 1961 and provides maintenance and overhaul services for both Continental and Lycoming aircraft engines. The firm now has a contractual relationship with Textron Lycoming to build experimental versions of several engine models from certificated Lycoming engine parts. All of these engines are for uncertificated, homebuilt experimental aircraft. Models available are specific versions of the G&N Aviation GNX O-320, GNX O-360, GNX IO-360, GNX IO-390-X, GNX AEIO-390-X, GNX O-540, and GNX IO-540. Details of their engines can be found on the G&N Website.