Earlier, Jim Carriere wrote:

Out of curiosity, how does the head go on ten
degrees (approximately or exactly) out of
alignment? I thought the bolts or studs would
accurately locate the head and jug every time,
so obviously there is something I am missing
or don't know.

For the cylinder of the common Lycoming and Continental engines, the
cylinder head is a machined aluminum casting that is screwed onto
threads at the top end of the steel cylinder barrel. Separating and
reassembling the head/barrel pair is something that relatively few
shops do, and I've never personally seen it done. However, I have seen
procedures for doing it, and I think it takes special heating and
alignment equipment.

Thanks, and best regards to all

Bob K.
http://www.hpaircraft.com