Currently a lot of people is selling Head Gaskets for K engine, claiming for equivalent to genuine.
I think this is the best doc I've ever seen, it's from DMGRS
Very interesting the details concerning the liner protruding versus the type of gasket.
I fitted the first N type gasket (kit ZUA000530) delivered to Italy at beginning of 2010.
In the past I started a 3D searching for field feedback for N type gasket, nobody answered. Does it really performs better, failure free.