What year make and model is block casting number d9ae-6015-ed-18 ford?

Ford began using this form of block casting in the late 1950's. They assigned each decade a letter which begins the casting number. 1950 began the coding with letter 'B'. Each subsequent decade received the following letter. The first number after the first letter is the year of that decade in which the part was modeled for.

This means that your block casting number D9AE-6015-ED-18 is for a:

D = 1970's

9 = 1979

A = the model is a generic full size Ford

E = the part is an engine component (or the complete engine)

6015 = it is an engine base assembly piece (or, again, the complete engine)

ED18 = the engineering version

In 1979, Ford produced the Ford LTD, Ford Custom 500, and Ford Country Squire in the full size models.

So, after all that, we know for sure that the engine is from a 1979 Ford and it's model is one of the listed.