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I think its properties are stronger than cast iron.


As per google:

Filler Metal and Flux for Braze Welding The filler metal used for most braze welding is a copper alloy containing roughly 60% copper, 40% zinc, and small amounts of tin, iron, manganese, and silicon.

Not as strong as cast iron. It may be "acceptable" but if i where trying the save a rare hemi block i wouldn't be brazing it.