x2, My napa has the same oil, and the same story.
Just done a search. Looks like most all the gl-4 oils are full synthetic, not sure if they are what we need, also some are listed as gl-5 and gl-4...
I think your on the right track. Defiantly need to stay with Gl-4 oil. I have not been able to find it locally either. If your current Gl-4 oil is...
I had an alternator with something loose inside that made noise once. just saying.
Separate names with a comma.