That number doesn't seem to follow the pattern of a factory ID. It's probably one that was put there by the rebuilder. Look for the casting number that is near the oil pan rail on the passenger's side front, and a date code cast into the block at the back above the starter area. Without a good stamped ID number, an educated guess about the original application will be the best thing available. Block casting codes usually span several years of production. If the cylinder head is off, the simplest way to determine engine size it to measure the bore and stroke.
Jerry
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"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
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