HOW TO DECODE A COMMON DATE CODE
One of the most popular questions asked is how do I determine my date code and where is it located.  The date code usually appears to be a bunch of "mumbo-jumbo" number and letters located somewhere on the part.  Date codes can be in several different locations.  The location is usually on the back area of the block, just above the transmission pad.  Keep in mind that date codes and casting #'s are often hard to read as time goes by.  You may want to thoroughly clean the area around the codes as to get an accurate reading.  3, 6 and 8 often look similar.
 
Month is the first letter in the code (See chart below)
A   JANUARY
B   FEBRUARY
C   MARCH
D   APRIL
E   MAY
F   JUNE
G   JULY
H   AUGUST
I   SEPTEMBER
J   OCTOBER
K   NOVEMBER
L   DECEMBER

Date is 1 or 2 digit # in middle

Year is the final digit. 
Keep in mind that the year can be different decades. 
Example, 5 can be 1965 or 1975.
Example date code, B 22 5, which is February 22, 1965
The Example above is casting #9778789, which is a Pontiac 389, the date code is B 22 5, which is February 22, 1965.