I have a Gruen 311 movement. I do have some other non working Gruen movements. Just curious what stems from othe Gruen movements would be compatible with the 311 movements. Advice appreciated, thank you.

Hey Mark,

The J. Borel website says that the following are all compatible:

Stem, tap 8, 200/399F

Gruen 311
313
330
355
400
500

Hope that is of some help.