DECODING X heads

[AJ71DUSTER]

I know that this Info is been review a thousand times before, but if some one would not mind to do it a 1001 it would help me out just a little, I have a set of X heads i need help decoding

here are the numbers

2531894-A

2531894-E

I do believe that this casting number is the date of casting 06248= june 24 1968

thanks