I do not know if the flange is warped. I do know when the turbo was off, we did not have a gasket on hand and could not source any locally, so we got a sheet of gasket material and cut to shape one. Needless to say, its not working very well. There was a thread here I can't find now (thanks search) that discussed thin vs thick gasket and wanted to know where I could get one. Thanks Mike!