It isn't that the "mid-years" head studs worked themselves loose, it's the thermal reactors that were required for emission control that caused a heat imbalance (too much heat underneath the engine, much less above) that caused the head studs to pull (uneven expansion rates, difering metals used in the case and head studs). Most often, 60K was/is about all you can do before you get to tear it completely down, insert some sort of case saver (huge debate just now about time-certs, etc), replace all the head studs, ensure the crank is in good shape, do a head/valve job, well, you get the idea.
Now, if the car is a '77, the good news is that the factory began a body panel rust prevention program that helps retard iron oxide. The car will be lighter than later model years, but not as light as pre-74s. These cars can be wonderful, it just takes 'Porsche" dollars to make it happen. Good luck!
|