The part is 95739. It is a 3/4" pin and 5" long from the bottom of the head to the end. This also replaces older pin # 41051.
Blizzard uses this on the 8600SW Speedwing plow to hold the wing to the blade and also on many of the Power Hitch 1 plows for the cylinders.
Western uses this pin to hold the 27170 conversion kit into the Ultramount. So if you want to pin something into your mount, this is the correct length. The head is 1" and 1/4" tall.
SnowEx uses this pin at the top of the lift cylinder. They also sell it with the cotter pin 85123. SnowEx also uses this pin to hold the receiver into the mount and they sell that with a cotter pin as part # 84611.