BB rpm and e street heads still use machined locks.

Just put a set together recently.

The “issue”’with 7 deg machined locks is...... seems like every brand has a slightly different installed height.

I can tell you for certain that Crane(not sure about the latest incarnation), Comp, Edelbrock, and the ones I get from my local engine parts warehouse are all slightly different, and provide slightly different installed height.

I don’t like to use “one” lock from another batch. If I lose one, I get another “pair” to install on one valve.