As stated previously there were no Chevrolet headers for 1969, either as an option or OTC. All the part numbers out there were developed for 67 & 68 Z/28s and supplied by Bill Thomas Race Cars or Kustom Headers. They will have the alternator mounting bracket on the LH flange, not required for '69. While they may fit a '69, it was not the design intent.
If you really want factory headers, the SCCA did homologate Camaro headers for the '69 season: 3965702 & 3965703. They were designed for the aluminum hemi heads so you will also need those.