so i am going to do a head job this weekend and i wanted to read up on
the trick of using a 13mm wrench to turn the cylinders when they are stuck
in the head. problem is that i haven't been able to find it in the
archives.  can anyone point me in the right direction or relay the trick
or other tricks again.

also what is the consensus on the bottom cylinder o-ring are most people
changing that or leaving it to chance?

jonathan