I had a lot of bad luck on the last head I did, first of all one of the head bolts was damaged by the previous owner which meant the hexagon socket drive just spun in the top of the bolt, I ended up grinding the top off with a small grind stone fitted to a Dremel tool. I used about 10 stones plus 4-5 hours grinding time, as you know there isn’t much room in there to fit a socket let alone a grinding wheel. The second thing that went wrong was I forgot to drain the block; I drained the radiator and removed it, but forgot about the block drain plug. When I lifted the head a small amount of coolant ran down the oil holes. The last thing was the missing cam seals, they say bad luck comes in three’s.