Hi Greg . . .

None of casting number lists I know of online go up that high. So I googled it - and came across a blog where someone is writing about a 292 transplant into a '49 Chevy Styleline that describes it as a Mexican casting circa '86.

This is at least logical because the sequence is higher then any of the castings documented online:
93403466 Chevrolet 75-83 250
93403467 Chevrolet 75-84 292
93406004 Chevrolet 75-84 292
both here and at Znet or ChevelleBB
though I am not sure why it would jump from 93406 to 93411 in just two years - (unless there was some sort of design/sourcing change).

The blogger seems pretty high on this particular block - praising the casting quality.

regards,
stock49

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