Head bolts how to tell if they are stretch or a grade 6-8

[lastlatvian]

So I am new to rebuilding Cher-man BMWs and I have come to the point of putting my head back on the block after a nice overhaul. I went to go buy my gaskets and the gent at the store asked me if i had stretch bolts. My car is a 1987 325is US model, I live in Canada. On the top of the bolt it reads RIBE 12.9

I cleaned the bolts threads with a lathe and brush but i was wondering do i need to buy another set now?

picture of the bolts, if another full shot is need just say, sorry if there is already a thread about this i did not find one in a search and i am in pinch for time

[Globulator]

Hex heads are old bolts and can snap off and get caught on the cam.
Little Torx heads are the replacement stretch and can only be used once anyway...



... so you need to buy a new set from the dealer.