I finally found the casting code. It wasn't where I expected it to be (it was in front and below the fuel pump). The casting code says it's a 261 from 54-55. Oddly enough seems to be missing the captain's bars near the starter and the code near the starter says it is from July 14, 1953.

Thanks to all of you for the engine color.

http://s299.photobucket.com/albums/mm282/dw_moto/?action=view&current=001.jpg