M-code A-body question

I ran a 69 GTX 440 in my 68 barracuda with factory A body 383 mounts. I don’t know why some 440 have the 2 mounting nubs and some don’t. Its not a new or old thing its just some do not. You can have a 69 with or with out and them and that goes for most year 440’s. For some reason The M code A bodies did not come with them.