From a chemistry perspective I can't imagine why sulfur might be good for an engine and many reasons why it wouldn't. I don't think there's any analogy to the transition to unleaded.
I put about 5000 miles a year on my 2007 F350 DRW, which I guess is a 6.0 (don't know if there were choices in any given year). No engine problems so far, did have a front brake caliper lock up and had a problem with the on the fly 4wd engagement that cost a kilobuck to fix. I mostly run close to GCWR with a camper (just got a new one!) and 8000 lb trailer with godawful aerodynamics. The power is impressive.