Generally speaking, most light and medium duty V-8 diesels were not real good engines, regardless of brand. Cummins made a couple, one was the 903 often referred to as the nine o nothing due to the lack of power. IH had one which I think CT is referring to that was problematic as well, mostly in the valve train.
Your best bet is to get an inline 6, nearly all of these are good engines. My choice would be Cummins, Cat and Detroit in that order. I don't think the Series 60 Detroit is available in the 8000, that would be on par with Cat in my opinion.
You might consider stepping up to the 9000 series Ford. Many fleets run these and the sell very inexpensively when they are replaced with a lot of life left to them. There's another
thread that discusses this option you might want to look at.