ID this trans crossmember, please

I ended up with the top crossmember with some 904s I was gifted. I think it was on a '63 slant 6 trans, but I didn't worry/ pay attention at the time, as I thought it was the same as the bottom one, which came off my '64 V8 Barracuda. Were the really early A body pieces different?

20231231_141453.jpg