I have a 4x4 sapphire cosworth and dismantled the head a while back. In doing that, I fu**ed a bolt that holds the cam cap nearest the pulley (one of two big ones at the front of the head, not the eight little ones).
The bold had an allen key head on it, which I ended up drilling out cos my allen bit slipped in it.

I have just tried to order a replacement, but no-one has ever heard of an allen bolt fitting for this, according to microcat, it should be a stud, washer and nut fitting.

Checked escos diagrams too and those show the same stud/washer/nut combination.

I am a little puzzled as to what could have happened there, any of you seen this before ?

Thanks in advance.
Greg