When you tighten your cylinder head fasteners, there are several things that affect the torque reading.  The torque wrench is simply a way to measure the friction in the thread system.  If the friction is high, the torque value will be achieved before the fastener is stretched enough.  If the friction is low, the torque value will be achieved at a point where the fastener is stretched too far.
 
When you tighten the head nuts, you are stretching the long studs.  Those studs act like springs.  The more you stretch them, the more force they apply to the cylinder head.  That force stored up in the studs keeps the cylinder head and cylinder clamped together.

I don’t recommend applying lubricants of unknown characteristics.  That’s why I tested a whole bunch of sealants and lubricants against the factory recommended lubricant (engine oil).  You can achieve dramatic variations in stretch with a simple change in lubricant/sealant.

This table should give you an idea.  Simply changing from engine oil to silicone sealant results in a reduction in stretch of approximately 53%.  That is essentially a 53% reduction in stress level.

Clean the male threads.  Crud equals friction, so get the threads clean.  A wire brush works fine.  Make sure the two studs that you removed are threaded into the engine case at least 14 turns.  The two studs that you did not remove should be ok.  If in doubt, take them out, suck out the holes in the case, and reinstall them to at least 14 turns.

See how nice the internal threads are.  You also want the flange face clean and smooth.

Clean all the spot faces on your cylinder head.  The right-front is hard to access, do the best you can.

Use a Q-Tip to apply clean engine oil to the internal threads.

For the remaining copper washers, coat one side with anti-seize.  These washers typically gall on the aluminum head.  The anti-seize reduces the galling but does not eliminate it completely.  You only want anti-seize on the surface that contacts the aluminum cylinder head.  I have only tested nickel based anti-seize.  Permatex 771 works fine for me.

Lubricate the internal threads and flange faces of the two remaining acorn nuts.  Clean engine oil and a Q-Tip get the job done.  Then install the LF & LR nuts.

It can be tricky to install the copper washer with the anti-seize in contact with the aluminum cylinder head.  A small rod or dowel works great for this.  Just put the washer on the rod, hold the washer while placing the rod against the top of the stud, then drop the washer.