Rocker arm, rocker arm bolt, rocker arm rail push rod, collapsed lifter. Most likely it's the rocker arm or the hold down bolt.
Be glad it's not a "bowtie". 2 friends just blew a connecting rod out the sides of their 350 Chevy engines a week apart! It's both their 2 crate engines in 4 years! THey said thay can't understand why these engines broke for no apparent reason. I pointed out the fact they're orange and say GM or Chevrolet is pretty apparent to me, and it's also the reason.
They just think I'm prejudiced no matter how hard I explain I'm more convinced than prejudiced.
It's why we have 7 FoMoCos at our house,
FBp