<VV> Head Torque - Valve Adjust

[jwcorvair at aol.com]

This past weekend I replaced the O-rings on my oil return tubes - tedious job, but not difficult. When I removed the stover nuts securing the rocker arms to the rocker studs, several of the studs unscrewed. Now, considering that the rocker studs are the lower head bolts too, I am a little concerned as to why the stover nuts would have enough torque to remove the rocker studs. 

Is this a common occurance? 
Were the rocker studs not torqued properly? (I used a "click" torque wrench set to 35 lbs to retorque the rocker studs.)
Could this be heat related? (My exhaust is very close to the head - custom exhaust.)

Not trying to start a religious war, but I normally adjust my rocker nuts while the engine is running. Now I am concerned about loosening the rocker stud/head bolts when I make this adjustment.

Any thoughts?

Regards,
Joe White (62 Sedan, 66 Porvair, 64 Spyder Project)