case stud identification please
 

Hello
Can someone identify these 964 head studs? They are all steel (magnetic) and have a 12 point inverted nut on them. Are the 12 point nuts used on the 964/993 case studs? My early 911 S and SC had barrel nuts. The heads on this thing are early 11/90 with graphite gasket ring in the barrels. how do I get that stuff out? Thanks for any help.
http://forums.pelicanparts.com/uploa...1347521785.jpg
http://forums.pelicanparts.com/uploa...1347521808.jpg
http://forums.pelicanparts.com/uploa...1347521828.jpg
http://forums.pelicanparts.com/uploa...1347521850.jpg

That head nut is 964 stock.
Bruce

Thanks Bruce for the response and for the explanation on my other questions.