arp head stud nuts for c20let

[rc]

my Lets nearly finished its rebuild and was already fitted with the head stud conversion, but when they were tightened up last time they must of used a 13mm multi socket, instead of the 1/2'', and rounded them off the tightening side. and i can't find anywhere to buy the nuts seperatly.:confused:

so has anyone got a set of nuts for the head studs? as i dont fancy buying the whole kit new? or anyone know where they do sell them on their own?