classic aluminum V6 parts

You are probably talking about the cylinder head? As I remember the engine block was still cast iron. Which V6? There was several 2.8L

They actually did make an aluminum block V6 in the 60's. To work on the innards of the engine, you were supposed to hold the block in a special jig. If you just left the block on the workbench or the shop floor, the parts might well not go back into it....