Anytime you want to read a Ford part #, the first character(a letter) indicates the decade the part was cast, and the second character(a number) indicates the single year of that decade. As far as I know, they began using this system in 1940, which would be A0. (though I've never seen a part that old in person) B8 would be 1958, C4 is 1964, D9 is 1979, and E7 is 1987 and so on.
The third character indicates which type of vehicle the part was cast for, T being truck, Z means Mustang, P for police service, V for Lincoln, O for standard Ford passenger car(I think?) There's others, but I can't recall them. Sometimes they're obvious, like T and P, other times they're ambiguous.