In 1980, I bought a new Corvette and at about 9000 miles, I started using Amsoil in the crankcase. Did so until I sold it at @50,000 miles. At about 30,000 miles I took car to dealer because of rough running engine...diagnosis was front lobe of camshaft worn almost round. Just after I sold it I found out that one cylinder of the engine had to have the rings replaced. I never abused this car.
Since then I have steered away from synthetics. Can you enlighten me?
I realize this post is old by I have information that may answer this problem.
Back early 1980 Chevrolet had a lot of problems with Camshafts. The problem was traced to one of their suppliers here in Michigan so not all the engines would be affected. BAD STEEL that had been imported.
I recall that very well. A friend had a new 1981 Chevy PU with a 350 V8. He had 2 cams replaced under warranty in less than 50,000 miles, the first one went bad early on. Finally when the 3rd cam started failing (he could tell by the engine running rough) and the dealer was reluctant to fix it, he installed a Crane cam and drove the truck for another 10 yrs and then sold it to his younger brother who wore it out. Btw-He as not using synthetic oil either. He had many heated arguments with the dealers to get his truck fixed under warranty.
Many of the out of warranty repairs were of the secret type, unless you complained loudly the dealer was not likely to admit the problem. Another one of those things that ended up costing GM customers.
I wish I still had the old service info on that cam issue but I have no idea what happened to it.