340 Hydraulic lock inspection update...
If the head passed pressure test I'd put a seat in it and run it.
Those are pretty beefy Pistons. I'd drop that piston out and if it didn't smash the ring land down on the ring, I'd buff the piston up a bit and run it too.
You damn sure need to figure out why that valve broke. Weak springs. Maybe just a bad valve. But you need to be sure.