[Dieselwrencher]

It really depends how it was taken care of during those miles. If it was maintained, it should be ok. We've got some at work that have 400-550k on them and are still going. Most if not all have a stock short block. The most work done to them is an injection pump, head gasket, and oil leak repairs. We have 2 12v's with over 23k hrs on them and are still going. They need mains rolled in as they are in gen sets and the thrust bearings are severly worn. I have a 90 12v in my 95 F350. It supposedly had 160k on it when i got it. We put 5k on it in the truck it came in, and then put another 150k on it in my Ford. It still runs great. Last year it finally had to have a head gasket put in it, but it runs stronger now than it did when i first got it. The engine in my Dad's 91 F350 had 142k on it when I put it in. He's put 145k on it since the swap, and he drives it everyday.

I've had plenty of customer trucks come in with over 250k on them, and we've done performance work to them and they all are alive except one. It blew the head gasket with compounds. When we pulled the head, #6 had scoring so it got a rebuild.

Moral of the story is, it could be fine and live for a long while. If you plan to buy it and reseal the whole thing, you might as well re-ring it and bearing it. The cost of the gaskets and seals would suck to do again in 6mo to a year if a problem would occur.