Rotella diesel oil in a 440 ???

It's not the cam bearings that are at issue with oil, it's the lobes. Modern automotive motor oil has had a lot of the zinc additives removed for polution reasons. This is not an issue with modern engines becuase virtually all have roller lifter cams. The zinc that has been removed was there to prevent scuffing as cam lobes slide over flat tappet cams.

The use of the oil is more of an issue with break in than as an ongoing issue but there is no down side to using it. Mobil also sells a similar oil that will do the trick.