Y Block Rod Bearings

[flatbedfred]

I am doing an in place rebuild of the 292 in my 57 Skyliner. I got the first piston out today and noticed that I have the copper rod bearings. Now I have not seen these before but I saw them mentioned in the manual. Is copper as soft as babbitt ? I don't understand how they can operate on steel, even with an oil barrier but they look to have done a great job!