I would be scared of that head even if it's still sealed up, and I don't know how it could be if the vavles hit (and bent). And hammered the guide bores and the rockers. I would buy an AMC or Clearwater head with hydraulic valves and no jet valves. I would also get a dye type crack tester and test the tops of the pistons. Rod(s) may be bent, too.

Now to the chain. Did you replace the chain and sprockets? New guides? New rubber tensioner block? New lower small chain guide on the oil pump drive? I think the guide bolts are small to start out with, but I think the guide must be getting hammered even with the small bolts to make them break. I don't remember the head marks, but I think they were the black 10mmhex bolts, right? About a 6mm x1.25 thread?