Dizzy Advance or retarded

[natvet]

Have and F engine but unsure if dizzy is vaccum advance or retard. (Not sure if PO changed from original)Any way to tell the difference by how it looks? Or will I need the number off of it? If it is a retard dizzy should I chunck it?

Thanks

 

[IDave]

If the points plate in the distributor moves counterclockwise when you apply vacuum to the diaphragm, it's an advance distributor. Clockwise, then retard.