Mustang Engine Stamping

John Booth (car 732) shared this info:

My son posted a question on the Ranger tech. board asking how to identify the engine year for Ford engines. Here is the reply: "I'm not sure where casting numbers would be, but the Ford numbering system is simple. It's going to be two 4-digit numbers, but the first two characters will tell you the year.

The first letter tells the decade. C is 60's D is 70's and E is 80's and so on... The second number is the year. For instance, E7TE heads are E (8) 7 (7) so they are from '87.

So if you find a casting number that says C9xx then the block is the '69 design. This is not a date mark though, it just means that the earliest it could be is '69. All carryover parts keep the original number, for instance the stock rods in an '89 302 shortblock have Cxxx rods in them, which just means that they were designed in the 60's. Hope this helped. "
  We found the number, D10E-6015, near the starter on s/n 732. This means that our block is a 1971 or newer.

11/01 - someone sent the Annexmaster this link which may be helpful regarding engine numbering on Mustang engines:

So I jacked up my '78 and looked behind the front wheel, up from ground level at the bottom side rear part of the engine. The letter "A" represents a little humpy thing on top of my starter motor (which appears not to be original) Above the circle is the exhaust manifold and the very bottom is the frame.
My car has only got the number 78, upside down as you look in from the side. I spun the camera around part way -- "A" is still the top of the starter motor. The back of the car would be at the bottom of the picture.
Now I am completely upside down, as if lying on my back with my feet out the passenger side. The 78 is on a raised area. When John sees these, he can report on how this compares to his car. Clearlly there is no room here for an 8 digit #. Also, this "78" is amazingly not very "coded"