The 245813010 is a casting number which was cast into the block along with the date code 5.5.67 , There should be a flat pad on the front of the block beside the distributor which will have a letter(year code) then the engine size(383) and then HP if its a HiPo or nothing if its a standard 383.

Are there any letters with the numbers? Like maybe the letter "G" or an "H" which stands for a 383.... Check out this site for more info: http://www.allpar.com/mopar/enginecodes.html Good Luck