I´m not the most qualified guy to answer your question, but I can tell
you about my experiences with my 1983 Surburban, also 6.2 Diesel.

The biggest problem with mine is body rust, but that is probably because
the previous owner abandoned it outside near the ocean for four years.
Given that, I´m pleased that there is any solid metal left at all. But do
take a good look in the wheel wells and on the underside of the doors.

I have ongoing electrical problems, but the condition of the wiring makes
it clear that the previous owner let someone unqualified work on it (crude
untaped splices, wires leading nowhere, etc.). So I can´t blame GM for
that, either.

I killed my automatic transmission, but that was my fault playing mountain
goat with only 2WD working. I rebuilt the tranny and installed a
temperature gauge on it so I don´t kill it again. These units have a bad
reputation -- others on this list can give you more details -- and if I
were buying new I´d get one with a manual transmission.

The brakes are giving me trouble, and at the least I´m going to have to
replace the master cylinder. On the other hand, it´s so big that when
other motorists see me coming they just naturally get out of the way. So
who needs brakes anyway?

The engine itself is bulletproof. The day I took delivery I drove it home
200 km on nothing but the sludge in the bottom of the fuel tank, and the
engine ran fine. We later cleaned the tank and fuel lines, naturally, and
what came out looked like crude oil. I replaced the injectors, but hey,
they were factory originals and 20 years old. I´ve hauled as many as 18
passengers (kinda cramped, but they fit) up and down mountain roads at
highway speeds with no problem at all.

So Pål, I´d say if it´s in good shape and the price is right, buy it.
I´ve just toasted to your success with a shot of good Norwegian linie
aquavit, yum.