Customs Block date code?

Where is the date on a FE motor. Motor is not in the car any more,so can’t even tell the year of car it was in.

 

look under the engine, just below the oil filter adapter.



On this one, 4 E 20 means 19X4 May 20th. The decade "x" isn't shown in the date code, but you can infer it from the first character of the casting number, which is located elsewhere on the block. C would be 1960s, D would be 1970s