Is This 452 Head Ruined?

I'm with @MOPAROFFICIAL .
As an engine machinist myself I'd say that is an easy fix.
I fix junkier **** than that for customers and never have comebacks.
Now if the ops is planning on running anything over hydraulic flat tappet spring pressure I'd say find another head but if it's stock and you can get 5/16 of thread depth there's absolutely no way it's pulling with 4 other bolts holding the shaft down.
That is a 30 minute repair. It doesn't need to be milled it is like cracked rods, the casting will set itself back where it belongs, id probably use a little jb weld on it and let it set up 1st. Then drill and tap it to a 3/8 if you don't bust it off while tapping it (with cutting oil) it won't break.
Wow, I'm surprised at some of these comments