Bronco would probably be the closest guide----as to what ford was doing electric wise in there trucks at that time

As for the valve train/camshaft---start it up and look to see if the lifters are rotating as it runs----any tappet not rotating will be worn on the bottom and the cam lobe worn

used to use some kind of cure all type pentrating oil to free up sluggish lifters as back in those days lots of the oil was non-detergent and a lot of sludge would build up causing HYDRAULIC lifters to not work very well