While cleaning the head bolt holes in my 5.3l I noticed what appeared to be a large crack in the water jacket. It seems way too deep to be some sort of casting mark, but another 5.3 in my garage has a very similar crack/mark.


What do you guys think about this? Should I be concerned or is this normal?
Thanks!

 

That's the casting parting line.

Nothing to worry about, it's normal.

 

I was hoping that was the case, but my inexperience told me to panic. Thanks bud!