Wow, that long for a cylinder head? I'll have to check on that. I can't understand why it would take so long, this engine has been around for a while.
I wonder, if they had a production problem with some heads, and that could be the problem.
Only engine I know of that was replaced was at the dealer I purchased my H3 from, and it was due to an oil shop forgetting to install the oil pan plug, before sending the customer off on their merry way. Needless to say, they didn't get too far, and this replacement did not show up under warranty, since the oil change shop paid the bill.
The SM told me it only took a few days for an engine.