If mine, and not knowing the total capacity of the block I'd pour 5 gallons or so of diesel in, let it set for a few days and drain. Do that a time or two till the flush fluid is somewhat clean. If the engine will crank, Hotrod Lincoln has a good procedure where you add a couple quarts of diesel to the oil overfilling the crankcase, then start the engine, letting it run for twenty minutes (DON'T DRIVE IT) the crank will whip the diesel/oil around washing the block like a solvent washing machine. That'd be my final step of cleaning. Drain the dirty oil/diesel and filter add oil, new filter and drive a while before deciding if a rebuild is called for.
Good Luck
RonR
