My mate has just rebuilt a 200 series v8. It picked up the crank and did the block with it. He came to the conclusion that 2 of the 8 injectors were out of sync , overfueling in to the bores. The diesel then got into the oil thinning it and end result was a new bottom end sent in from oz. Not entirely sure how you could look out for this other than checking for any trace of diesel on the dipstick or a very feint rumble from bottom end. Since he did his we've heard of 2 or 3 other cases the same. Not trying to put you off because they are fabulous trucks. Just a heads up.