I'm trying to remember what little I know about the starters. I just counted the teeth on 3 starters I have, knowing they came off my 216's that were in my 51 & 53. I come up with 9 teeth. The only difference I can recall is regarding 6 volt vs 12 volt changes to the flywheel. 139 teeth vs 168. The size of the starter drive shaft and gear changed also. I would assume the 30 & 40 startes had 9 teeth. If I can document it I will let you know.
