The automatic starters will work in a 4 speed but a 4 speed starter will not work in a automatic. The thin band on the starter nose is typically automatic and the wider band is for 4 speed. It has to do with how far the Bendix push's out to engage the fly wheel/flex plate teeth. I posted a picture showing the different in the outside band used for identification and the nose cone difference on how far it sticks out. The Bendix in the auto starter has to go out farther to reach the teeth of the flex plate . The 4 speed starter does not have to go out as far to engage the teeth of the flywheel. Mix ups happened . Here is a vintage photo of a automatic starter installed in a 4 speed car. There is a later SA TSB about it because it was a ongoing mix up problem . You can always ask a starter rebuilder versed in rebuilding the earlier Ford starters about the nose as it applies to a 4 speed vs automatic .