[rotorwrench]

Aircraft engines use several types of what are referred to as piston pin plugs since most have floating piston pins. Some plugs have a light push fit outside of the piston pin and fill the whole pin bore. Other types fit into each end of the piston pin with a piloted stub and can be either a light push fit or a tighter press fit. Most of these are only a bumper plug and don't fill the whole bore. Some are made from harder aluminum alloys and others are made from a softer copper aluminum alloy and have a gold color to them. All of them work pretty well as long as they are replaced at each overhaul.

I don't know what Ford used with their steel pistons since I haven't worked on any that old yet. An engine rebuilder that works on a lot of old flatheads could likely add more to the story than I can.