The quartz movement from Mustangs Etc. is a nice, tight little package that is easy to install into a Rally-Pac or any other Ford clock face.

This exploded view provided by Instrument Services demonstrates how the quartz movement ties into the original clock gearing and face. Instrument Services provides clock repair, clock repair kits ...

Read about upgrading A Second-Gen Firebird Clock To Quartz Movement by High Performance Pontiac ...