I would worry about introducing a diesel oil to an older engine that hasn't been running high detergent oils in the past. I blew up a company Chevy 350 in a pickup doing that as the detergents washed all the carbon out. IMHO, safer to run automotive oils unless you run the diesel stuff from the beginning.
(edit: I gots my jen-you-ayn army surplus kevlar hemut on my head. Let er rip :^)