Well, no doubt there may be some beginning signs of engine wear elsewhere
(just kidding) but I'm having a difficult time finding something anything
else to buy right now so I'm trying to just keep this thing running a bit
longer.  Rebuilding an entire engine is beyond my experience and I need to
do a lot of research before buying a rebuilt engine mainly because there is
a huge price difference on various rebuilds and I don't yet know why.  I'm
hoping that the worst thing wrong with it is a head gasket but if the block
is cracked then I would be wasting my time trying to replace the gasket.
That's why I'm asking if there is no water in the oil are things probably
not as bad as a cracked block.  Is there some way I can tell before tearing
it apart?  I've read a lot of old posts but could not find the decisive
answer.

I agree that it would be foolish not to at least do a valve job while the
heads are off and once I get that far a rebuild is staring right at me but I
also have to consider that the rest of the truck has 280,000 miles on it too
and needs some work that may be costly so it may not be worth putting $2000
to $3000 or more into the engine.  But a hundred bucks or so for some
gaskets won't hurt too much and would at least get me to the used car lot
;-)

Aside from the problems I described the engine runs really well and still
has quite a bit of power.  The good news is that I replaced the radiator and
put some Stop Leak in it and the engine is now running pretty smoothly and
there is no more white smoke out the tailpipe.  The Stop Leak I used said it
would repair a cracked engine or blown head gasket so I guess maybe it
worked, at least temporarily.

One of the problems is that with the internet there is so much information
about problems with cars and trucks that it sounds like nothing is any good.
My conclusion right now is that Fords are crap but they are better than
anything else ;-)  Is it getting hot in here?  (flames are coming, I can
feel it)