67 BB frame mounts - question

[68Zproject]

Bottom pic is drivers side.

Well, at least it's on the correct side then so not swapped side to side.

[bergy]

there were 2 different bolts in securing my frame mounts

[bcmiller]

I would say both original. One has same markings as what I posted.

I have not seen this before and so far can't find anyone else that has. But this had to have happened more than twice.

[arocars]

It doesn't look like your motor mounts would have moved the engine forward for additional firewall clearance, like the link posted above mentions. My first thought was to swap sides, but you mentioned that they wont swap due to a flange on the trailing edge. So, I would conclude that they are wrong for your car and replace them. Figure out what they are later on.