its not a home job unless there is an obvious crack that you can see immediately. There are plenty of diesel engine specialty truck places which do it and there should be quite a few near you. They are usually very helpful and will give you the lowdown over the phone.
yeah the head is off, my old man and i did it this afternoon. trying to get an uncle of a mate to test it, just hard to find a place to do it round the silly season.
used an 8 foot long street sign pole (from my little bro's juvenile delinquin days) over the breaker bar on one head bolt that really didn't want to play, showed a little surface corrossion when we got it out. shattered a couple of sockets and adaptors before we called in the sidchrome.
that was the only difficulty, along with the injector lines. and the fact my old man has a bad back (worse now and those heads are heavier than they look.
You get what is called magnafluxing done. They use a dusting of iron filings or something and then magnatism and the cracks show up plain as day, even if they are invisible when looking otherwise. The guy will probably leave the filings on to show you where the cracks are. I've had it done several times. Not expensive and relatively quick.