What’s the “H” for on 915 heads?

Bennoel 10 said
Not trying to be disrespectful as I get the feeling I have offended some. I'm just trying to help/share what I believe. In the bottom picture of the X head I've shown is a # 09238. This is upside down in the pic. I believe this to be the actual casting date
09-sept.
23-day
8-year, 1968
Again I believe the letter that follows the casting # only tells what casting box it came from.

Insult someone? Disrespected them? They’ll get over it.

Bennoel 10 said
Me either. I don't believe that syleng1 is saying he has "H" or "C" head. He is asking what are these letters following the casting numbers for ?

I realized this later that it was as he straightened out in his last post.