1965-1972 1/2 Opel CIH engines had a 'short' cam button, while later engines had a longer button due to the redesign of the front of the head when Opel changed from a 10-bolt to a 12-bolt fastening. The thread pitch is metric in the camshaft, so it's unlikely a Chevy cam button will cross over. Use the later Opel button and cut it down to length. This button is critical, it is the only thing that prevents the cam from walking forward, which will wear the lifters badly and also potentially break the timing chain.
Bob
Bob
