On a different message board a guy says he uses shell rotella 15w-40 in his 1970 442.He states it has more anti-wear agents than the regular motor oil,and has used it for years with good success.Comments please!
I see no reason why you can't use the Rotella oil in a gasser. While having a rating for Diesels it also is rated for gasoiline engines (API SL, SJ, SH). The main concern for diesels is soot control and anti-foaming where the gassers don't require these properties to the extent a diesel does.
With the Ford Power Stroke, the injectors are oil accuated with pressure reaching 3000psi at max rpm of 3400. With the injectors being oil accuated, you need to control foaming so they don't aerate (sp) and the soot control to prevent clogging of the small passages in the injectors. Yes, the engine is an International NaviStar with Ford computer controls that limit the rpms and horsepower. Also, the PSD has a roller hydraulic cam.
You can read more here:
J.S summed up the ratings which say it is ok for petrol.You could look at it this way,The diesel oil withstands high compressions + it is also good enough to lubricate turbo's in a lot of cases and diesels last a long time..