Vibration Damper for Internal & Externally Balanced Small Block
I have a nice used Summit Racing SFI approved vibration damper part # 64278 for small block engines. This was used on a 360 stroked to 408. It has 60 degrees of timing markings as well as a marking every 90 degrees. It is made in Australia.
The damper has a weight that can be added for externally balanced engines and removed for internally balanced engines.