Again, HEADS have nothing on them. They are flat. IF there is a mark that you can feel, the head is in need of exchange/machining. The pic above indicates water in the combustion chamber. See the little pits that go up to the seats? If they were just pocked around the face and not at the seats, i'd call it good, but, what you can't see is if the coolant has, due to the pitting on the seat and head, found a way between/under the seat. When that happens, seats drop and cause ugly damage, repairable if it is shut off, but alot of work. If it were me, I would buy remans. Also something to remember, these things don't do the miles that trucks do, so, there s a 50-50 possibility that nothing will happen, or will happen. Just would suck to have to do the work twice.
And yes, seen it happen. "Budget" overhaul, nothing wrong with that, but heads recommended just for this reason, customer declined. Put it together, dyno tested fine, the customer took it and a couple of days later, back on a hook with a bad knock. Dropped a seat on one of the better heads, debris throughout the engine....when seats drop, the pieces parts will bounce back into the intake and visit other cylinders wiping them out...also took out a cam follower pin, it was a big cam, those were tough. A small cam weak link is follower pins. Assumed warranty, when it was pulled down and found the root failure, the guy was not happy. Ended up doing a high dollar NOW overhaul