High-mileage 915 J heads... can they be fixed?

So it's not an A-body but since I got my 1972 D200 with a 360 running it always idled like crap even with a nice 4-bbl conversion and full ignition tune-up. Well last night I was in the process of installing some headers and broke the rear exhaust manifold stud on the pass side head. I had a feeling the exhaust valves were sunk based on how it ran and I could see the valves look burned from the open exhaust ports. Got the pass side head off and sure enough, all the exhaust valves are sunk to varying degrees with one almost 1/8" down.

Question is is that repairable? Also will I need new exhaust valves? I'm kind of leaning towards just finding another set of 360 heads in good shape to throw on; I just want to get this truck running again so I can use it to help move my stuff to my new place in a couple weeks. I'm not trying to build a performance engine either, the ultimate goal for this truck is a 12-valve Cummins diesel swap anyway so I don't want to spend any more on this current 360 than I need to just to keep it running reliably.