Possible crack in 340

[Jaymz]

This block has couple other like this

 

[RustyRatRod]

Hard to tell but it looks like a casting flaw to me.

 

[MoparMike1974]

I agree, looks like a casting line. Magnaflux it if you have doubts.

 

[413]

That is a casting line. It’s not a flaw either. Look over some clean blocks and you will see that is common.