Thanks for the info HOTRODPAINT. I will check into that further. They are certainly an earlier part so the 62/63 codes make sense. The motor is not the m code though for sure ( too bad ..lol) I only paid 150.00 for it and im pretty sure at the very least it will be a good a running motor as it is, after a good cleaning , a few gaskets, some good oil and a tuneup. Thanks very much for the great info. and i will add anything new I come up with.