anyone help decode an engine
 

it is a big block chevy casting number is 3969354,(have picture)not 9854,, and the pad # is T0301CLB, I come up with 69-72 402, how can I tell what year exactly is this engine? any help will be appreciated.

i looked the casting number up and it says it was a big block from 72.

On the side of the block there will be a casting date.
Example C 24 0 . C third letter means 3rd month 24 day of the month 0 is the year 1970. Hope that helps.