The piece of mind thing should basically be out the window now with the 3.0L's and all of the controversy surrounding it. There have been theory's behind the spun bearing forever now. Is it crank walk, is it the oil galleries, is it the Casting Process. I'd rather "chance it" if you will, on a low mileage salvage yard motor(which I did) than to spend even more on just a short block, to have the same thing possibly happen. But to each his own.
Mark
