Advice on buying junkyard engines?

These pictures are from a big block Chevy that my brother purchased used a few years ago. Seller claimed that the engine ran perfect, lots of oil pressure and tons of power. The only salvageable parts are the aluminum heads, intake, and possibly the rotating assembly, though the crank and rods will need a visit to the machine shop. He trusted the seller and paid top dollar for it, but never got around to opening it up until last week.

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