While I haven't looked lately, up to about a month ago I was finding CI-4 15-40 oil in almost every parts store I went into. With the findings from Gil Baumgartner's study, it looks like the CJ-4 oil is okay.

54 Victoria 312;  48 Ford Conv 302, 56 Bird 312
Forever Ford
Midland Park, NJ

hey guys.  I was at the local freightliner dealer putting in a app and happen to pop over to look at the oils and they had mobil 1 5/40W synthetic that has the CI-4 Plus api rating. now, this is the only 5/40  oil i have found with the CI-4 plus(higher zinc content).