ci4 oil is still available you just have to know how to buy it. the government stoped all ci4 oils from being sold in quarts and gallon containers but is still available in 5 gallon and 55 gallon drums. the distributors carry both ci4 and cj4 oils in 5 and 55 so you have to specify the one you want.
I tend to agree with Harvey but I did get 20 gallons of Valvoline Classic (ci4+) at NAPA while back. I stocked up b/o I wasn't sure how long it would be available. I will continue to use CI4+ as long as I can get it. I do remember ready somewhere on this board that some engine builders are recommending an additive with CJ oil after cam installs. They were starting to see pitting in the cams with CJ oils. I didn't use any additive after my cam, but I've always used CI oil.
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The bottom line is simple; these oil additives are making money for those that are producing it!
that line summarizes the entire issue very effectively and clearly. It's all anyone really needs to know.