biggest solid slug of metal?

That ship engine block probably went together either two or four cylinders at a time. Even though I think I'm the one who posted it, I'm not exactly sure what the deal is. I do, however think that they have engine blocks that "stack" together to make 8, 10, 12, 14 cyl. models. etc.

If you look here you will see that the "block" is bolted up out of modular sections:

The largest ingot casting I have seen would rival the 350T casting, unfortunately it was the result of a ladle freezing solid, and it only lasted as long as it took for someone to get round to cutting it up.