This is the clevis pin that lives in the push rod fork for the brake master cylinder. The brake/clutch dual master cylinders use the smaller of the clevis pins shown, while the later (1968-on) dual LINE brake master cylinders use a longer clevis pin. If you have the later style set up with the divorced master cylinders for the brake and the clutch, you will need one of each clevis pin (larger one for the brake master and smaller one for the clutch master), while if you have the single master cylinder in place, you will need two of the smaller clevis pins.
