Mine,as with others,is on top of the frame,on the drivers side,next to the rivets,holding the x-member,to the frame rail.I started with toothbrush style fine wire brushes,to remove rust,because the stamped numbers are not deep,and might be worn away with sandpaper or some other abrasive.I finally saw one of the stamped stars,located at both ends of the number.Carefull not to wear them away,some are almost unreadable,due to being too easy with the hammer when they were stamped.