In a gas turbine engine, coolant (e.g., cooling air) is prone to leak out of the interface between the combustor case, the nozzle of the turbine, and the exhaust diffuser. Embodiments of an interface are disclosed that provide non-fretting sealing using an interference fit between radially facing surfaces of a combustor flange and diffuser flange. In addition, one or more contact sealing lands may be used between the combustor flange and diffuser flange and one or more seals may be provided between various components of the interface to provide additional sealing.