 The late style being the clean short one. 
The nose on the later style is about 26.5mm. 
The early style is about 33.5mm. Measurements were eyeballed but the difference is big enough that doesn't matter for IDing them. Just to note, the pin on the late style cam would be the same length as the early style but I'm using the JWT spacer kit to run some early style intake cam gears with the late style cams.

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