I am not sure about these cars but I was recently told the k-members where the same. Don't know how true that is.

I have a 73 that had a 440 in it but it originally had a 318 in it. I remember my dad telling me that he put a kmember out of a BB cordoba in it, but like I said, I had a guy tell me that didn't make sense because they should have been the same.