casting number?

Is the distributor in the front or rear? There should be casting #s on it. Are these #s on the front? Could it be assembly date and engine seq.? 3153 on the 10,000 day calendar would be Mar. 16, 1970. Are they stamped #s? May be an "F" for 1970. "E" is for 1969. Let us know what you find out. Ray