Just snapped off a camshaft bearing cap stud (while torquing according to the specs) pn a 1987 740 GLE. Where do I get a new piece? How are these fastened in the head? Are they screwed in with loctite? What a bummer. Was doing well replacing the oil seal, or so I thought.

 

You could use 8mm all thread or find a stud at the auto parts store.
The stud may have loctite on it. Center drill then add some heat, like propane to break the loctite, then extract. Those nuts don't get that much torque.
Ed