I have a 1979 Mark V with a 400 Engine, it has noise in the upper end. I was wondering if the valves are adjustable on this motor.
The valves are not adjustable in the manner that we would like in order to eliminate the upper valve noise. The noise should be diagnosed and pinpointed accurately as it may be a worn part or parts in this area that will need replacing. Technicians will also consider such items as engine mileage and engine oil pressure etc. when diagnosing upper end noises such as you are experiencing. The FoMoCo shop manual for the 79’s has a very good engine section describing engine noise diagnosis.