Virtyually all the rebabbiting done these days involves pouring the soft bearing material into slightly undersized molds that position the connecting rods or main bearing bores correctly, and then the Babbit metal is machined or honed to the finish size. Original equipment GM rods were formed by a process called "Centrifugal casting" where the rod was mounted into a spinning fixture and molten Babbit metal was sprayed into the preheated rod to form a thin, very tough layer, harder than most modern rod bearing material. I can tell if the rods I'm fitting or machining are original or reconditioned, by how the metal cuts- - - - -original GM rods will actually dull a high speed steel cutter bit after a few passes. Poured Babbit cuts like butter!
Jerry
