i'm getting more and more confused.
i've included photos of parts from two other online companies for 1967 "replacements". one is the bolt in tapped shaft, the other is nut on threaded shaft. the part i received is also a bolt in tapped shaft, but without the dumb bell shape.
i'll double check my before disassembly photos to see which side each came from. i'm sure the holes are the same distance apart as well, just distorted due to the camera angle. will check that as well.
I have owned a fair number of '67 LOS cars and seen a ton of them over the years since I live on the West Coast. On '67 LOS cars it is not uncommon at all to see mismatched shafts from one side to the other. The dumb bell shaped one at the top is most common (and is what you see all the time on the NOR cars) but the style like what you show in the middle is the other style which I have seen as factory installed. However, the factory ones have GM cast on them with a series of numbers after that. These are what you most often get when you find NOS replacements but rest assured they were also factory installed (but only on '67 LOS cars as far as I have been able to tell). That shaft on the bottom is not a '67 Camaro piece. It looks similar to a 2nd-gen Camaro shaft with the nut being installed on the threaded shaft rather than a bolt threading into a tapped hole, which is how the 1st-gen cars were done. Is the center-to-center distance between the two holes the same on the bottom one as it is for the others? Your picture gives me the impression that the holes in the bottom shaft are just slightly further apart than the other two.