I too have read that the amount of zinc (sulfated ash) content in oil will go down in diesel oils in the near future. It is unfortunate because Rotella is cheap and readily available. I use Rotella in my 'Cuda now because the 340 was built back in 1980. At the time it was built, had the largest hydraulic flat tappet purple cam available installed, so the big springs are hard on the cam and lifters due to a tight 108 LSA and a lift over .500". I guess that if we have to go back to conventional oils, then a camshaft/engine break-in lubricant will have to be added at every oil change.
One of the articles I read recommended this. The author said he had been doing it for years. When I was at a super wal-mart the other day, I noticed an oil forumulated for vehicles made previous to 1988. I believe it was one of their house brands. Does anyone have any info on this oil? It was pretty cheap too.