That is what I am seeing too. I think in 1969 up they went with the long flat connector when they moved the ignition switch to the column from the dash. My 1977 Firebird tilt has the flat one. All my later standard columns have the flat one too. It clips to the tabs on the side of the column to hold it in place. I think all the 1967-68 columns used the round one, but why make separate wiring harnesses when we can just sell an adapter? That way one-size-fits-all and we sell an extra part. So the round one that is in my car now is probably correct. The flat one in my parts column may have been replaced with a later one. I think that makes sense.