US Car Tool A518 Cross member

Hemming’s article states “.....GM stud-type transmission mount (#10473052) ......would have less offset than it will with the taller Mopar mount (#52019615)....”

https://www.hemmings.com/blog/article/chrysler-a-518-overdrive-transmission/

Everytime I Google that number, I don't come up with a factory mount, only a poly mount. I also work at a GM dealer and that doesn't come up as a valid GM part no. Where did you get yours?