I would use a touch of blue loctite and set them
to the proper height, not based on torque specs. You can check to make sure you don't exceed the torque spec if you are worried about that. Do not bury the unthreaded portion of the studs with force!
The depth is given in the PET. So for example an 8 x 35 stud is an M8 with the exposed side showing 35mm above the case ... I believe. Someone can correct me if I am mistaken with the spec here.
Here is a thread on this subject.
911 Engine Case Stud Studs - Install Torque