ALL nuts on the top of the head, such as rocker block nuts and rocker cover nuts only get 5 ft-lbs torque, no matter what any workshop manual says.
Head stud nuts get 20 ft-lbs, not the 24 the manual says.
These figures are well tested and very accurate numbers that will hold all the respective items securely without pulling the studs out. It is extremely important to not pull out the studs because the alloy is soft and there isn't enough material to securely hold a Timesert and a Helicoil won't hold either. You might be lucky and get a thread repair to hold, but very often they will pull out too.
The moral of the story is to use my torque figures carefully and hope for the best. I have a LOT of experience in this area, and you would be very well advised to heed this. I have seen iron barrel Bullet heads that we could not repair, and I worked in one of the most advanced racing shops in the country when we built our Fireball engines. We could work miracles, but when the heads go soft and start pulling studs, it can get very bad.