Hot Rods flathead question

a friend is building a flathead and has had it decked to make sure he had a good mating
surface but is worried about taking to much material from the head stud threads .
your ideas please ?

 

Has the block been decked before? Usually if you are having a block decked to make sure it is flat you arent going to take more than a few thousandths off(010 " or less typically) unless something is very wrong . That shouldnt have much affect on the head stud threads.