If it ain't broke don't fix itAll:
I am considering replacing head gasket on a 1991 cabby. Not because I have any of the symptoms - milky discharge on oil cap, smoky exhaust or coolant leak......but because the car is 31 years old and its never been replaced.
Cabby-info list replacing head gasket as a periodic maintenance kind of activity.
Trying to ascertain whether that is a valid reason for going through the trouble.....
Parting shot: Do I have to get the head machined at a shop?????
Just thinking out loud....