I thought you have the long studs,ie you have only 4 or 6 the rest are std bolts ,and do not have thread on the face but the stud go down in the water jacket between the sleeves.Is that right?These should have a rubber o ring in the middle to prevent water coming up the stud and leak from under the nut.
The other type are the ARP studs (short),these are screwed instead the original bolts so you have the threads in the face of the block.

Roger