Looking for casting numbers? This might help
They aren't free, but there is a wealth of info available.
http://www.angelfire.com/sc2/AACNCCLUB/ENGINE_CASTING_NUMBERS_AACNCCLUB.html
This next site is the American Engine Rebuilder's Association website and if you join, you get a manuals listing all the casting numbers on heads, blocks, and crankshafts. I used these books when I worked in an engine machine shop, and found them to be very valuable. They have lots of other helpful too:
http://www.aera.org/main.htm


