I had to replace 3 of the 4 exhaust studs on the 5.2 in my 1998 B1500. After I screwed the new ones in and put the heads back on the engine, I read in my manual, it said that sealer should be put on the threads that screw into the head. The stud holes are blind holes that don't go into a water jacket, so do I need to remove those studs and put sealer on those stud threads??? None of the bolt holes go into water passages.

 

If they don't leak water when its up to temp, and cooling system is pressurized, I wouldn't worry about it.

 

If the holes don't penetrate into a water jacket, then there's no need for sealant on the threads.