I just bought a 50 Dodge Coronet Club Coupe, in pieces, with a parts car. The fun begins. I plan to go with a small block Mopar and lower it, after, of course, the requisite rust repair, etc. The flathead that came with it has a number stamped on the block of IND5A257570. It's on the left side, between cyl 1 & 2, right where the number is supposed to be. I can't find ID for that. Can anyone help?