If your going to remove your headbolts its a good idea to replace them they are pretty cheap ajusa?? make them.
I have just fitted ARP studs to mine . They are a prick to fit and torqued up had to machine down a 1/2inch extra long socket so i could get it on
A 10mm hex should be easy and cheap to buy the 1/2inch extra long socket only cost me $12 all my tools are metric as most datsun stuff is the threads are metric but takes 1/2 inch socket??
Good luck with it