<VV> main and rod bearing question

[JUDY HOOK]

I have a question.  Does anyone know of a bearing manufacturer that makes copper clad bearings?  I tore apart today a '61 98 hp engine.  I first noticed the rod bearings.  When I took the first cap off I noticed the copper color.  At first I thought I was looking at a junk bearing worn all the way to the copper layer.  Imagine my surprise when I saw all the rest of the rods and all the mains looked identical.  Inquiring minds want to know.  Thanks for you help. 

Randy (Cap'n) Hook

Hopewell,  PA