How many of you have basically never had any serious issue with your 80's? (1 Viewer)

[DirtyPepper]

"are there any obvious external indicators that the HG has already been replaced?"

One possible clue the HG has not been replaced is the presence of the original off-white FIPG around the half-moons. However when the valve cover gasket is replaced the half-moons are supposed to come out, be cleaned up, and new FIPG applied. Often the replaced FIPG is black, but not always.

You could also look very closely (take photos) for tool marks of the various bolts that would normally be removed/reinstalled during a HG replacement.

Having said all that if there are no leaks from between the valve cover and the head in a 97 model, then the valve cover almost for sure has been replaced,
at least once, possibly twice since the vehicle left the factory.

Look closely (take photos and magnify) at the bolts holding the valve cover down, do they appear turned? Of course if the prior owner replaced those bolts then they won't have much in the way of marks on the flats of the hex head.

For peace of mind you could collect a sample of used engine oil and send it off to Blackstone laboratories for an Engine Oil Analysis (EOA). That can show if there's unusual levels of wear metals or signs of coolant in the oil.

FWIW.

I appreciate the long reply...all of this is good to know!

I'll take photos either tonight or tomorrow and post sometime over the weekend.




Thanks,