The worst one I've yet torn down had a busted cam when I got it and I figured it was from a stuck valve. The previous owner had tried to start the old truck by pulling it with a tractor and dumping the 11 inch clutch. Needless to say, it didn't start. As it turned out, it also had driven a hole through one of the lifter tops too. The saving grace was that I was able to get the cam out since it was broken which allowed me to get the busted lifter out. Most of the valves came out after removing the springs & keepers but one I had to drive out from the bottom then I could drive the guide out from the top. What a mess that one was but it turned out to be a really good block. Funny how things turn out some times. I got a good one but I really had to work for it.
Kerby