240Z TwinTurbo

Careful I am, lucky I am not. It's an engine, just like all the other engines i've worked on over the past 25 years. Don't need a lecture from pretentios Porsche folks regarding the importance of keeping the head surface flat because its has high pressure oil passages. That's the same for all engines so nothing special about the 928 except the cam tower gasket is fairly thin. Don't mind the fact that razor blades cause considerably more damage to the surface vs a scotch brite pad and that is how you have to clean the head to remove the cam tower gasket. The OP expressed his appreciation for the varying views and will make his decision accordingly, as it relates to cleaning up scratches on the intake manifold, which I recommend using a fine surface preparation disc on a 1/4" angle grinder turning at slow speed.