I'm pretty sure this is not the right place for this discussion, but...
I'm guessing advertised tool head is a bare tool head with no dies, but if it were a 38 Special tool head it may or may not have a different Angel Lever Cam. Progressives use the #49 Angle Lever Cam, and Universals use the #49U. However, you can load 38 Special on a Universal as well as a Progressive.
When purchasing a tool head, it is important to know if it came from a Universal of a Progressive. A tool head from a Progressive will not work on a Universal unless you change the Angle Lever Cam to a #49U. If the tool head has dies and they are anything other than 38 Special, then it's a pretty good bet it has a 49U. If it is 38 Special tool head, it could go either way.