I mentioned the old B&M Hydro-stick Hydramatic's a while back. and just remembered this old link to more info on them and on the "stock" Hydramatics as well. If nothing, the link will provide you with more info on these ancestral Hydramatics. Read and enjoy.
https://www.jalopyjournal.com/forum/...stick.1246713/
There are links within the above link to guide you to more in depth info.