block symbols???

[JoseyWales]

Over the weekend I was working on my car and while working on the motor I noticed an International Harvester symbol on the block. Whats the deal with that ? Its a 318 casting date 6-22-1977 I pulled it from a 78 Plymouth cop car. Any ideas?

 

[clhyer]

How about a pic of that?
Thanks,
C

 

[JoseyWales]

Ill try and get a picture of it, though there is not much room in the early A's. Its cast into the passenger side of the block. Its about 3/4" in size and its an I H, with the I in the middle of the H. I saw it and was just curious.