I wanted to remove the head from an old stuck K0 engine. It was found outdoors in the dirt, the dyno cover is welded it looked awful. I got the rocker cover off and spotted a rusty late model cam, 6 different bolt heads holding the cam towers on. Not looking good. The outer head bolt holes are too small for my socket so I ground one down to fit. It went in, I turned it, it split and tuliped on the inside between the fins! After an hour to get it out. I ended up using PB blaster, a wrench between the fins and a phillips bit in my battery impact. It finally came apart.
The good part, I noticed aluminum retainers and triple springs, probably had a big cam once. Then I looked into the intake port, It's been ported! Popped the head off and yep, an 812 kit. Stuck like it's welded but you never know, a few helicoils, guides and valves and the head might be good to use.