The head studs on a 911 motor do not thread into the head, as you describe, but rather pass through the head(s) and cylinder jugs, where they thread into the engine crank case. The jugs and heads slip over the studs, (135mm long/exposed, installed), then 24 special flat washers and barrel nuts secure the heads/P&Cs to the case. The torque value for these fasteners is approx. 25lbs. (Don't have my books handy). You couldn't strip a stud w/ 25lbs.
if you wanted to.
The cam towers do not need to be installed to attach heads. They use separate fasteners. See photo:
Once again, a photo would clear up the description, but if not possible, could you be referring to a cam tower/head stud, the small ones that protrude from heads to attach cam towers, (12 on each side of motor I think)? What torque value are you using on both sets of fasteners? Which books are you using?
