A company called ARP makes all kind of head bolt, studs, etc. I wouldn't be surprised if they offer a kit for that engine, not that it does you any good at this point. You might try getting info from a web site, turbo diesel forum, lots of good info there.
Also, even though I truly like Toyota trucks, especially the 20R & 22R 4 bangers ( just bought another, a '95 a couple of days ago ), the Japanese still can produce problems, look at the early 3.0 Toyota V-6. If engine oil wasn't changed religiously, they would sludge up, causing head gasket problems, etc. There are plenty of other examples from the land of the raising sun. I think what the Japanese makers due is to keep customer loyalty by doing their very best to correct the problem, do repairs even out of warranty, etc. THAT is the ethic that puts them ahead, in my opinion.
Mark