http://www.classicmustang.com/decoding_part_numbers.htm
http://www.ford-y-block.com/fordpartnumbers.htm
http://raceabilene.com/kelly/hotrod/engine2.html
They have just about all you will need to ID a ford block
That being said, are you sure thats the block number? Doesnt look to be long enough. Hunt around for other numbers on the block.