[77newell]

The early Series 60 engines (early to mid 90's) did have some kind of flaw thar would throw a rod through the case. Changes were made and that problem went away. There was no test that allowed you to see that one coming. Since then, keeping up with maintenance is all you can ask for. That, and an oil analysis on oil that has seen some use (you learn nothing by testing new oil).

I would also suggest reading everything on this site from owners of coaches of the years you are interested in. If you are mechanically inclined you will likely learn enough to ask really good questions and be able to assess the fit to yourself.