Ed, Two years ago I was in your same predicament. I ended up putting a
new GM crate motor in my truck. In my case, for my '89, it was only
$200 or $300 more to go with the new motor (and 3 year warrenty)vs
rebuilt. I did look into rebuilding it myself, and was looking forward
to it, but the logistics of taking my daily driver down for that long
necessitated a quick turnaround.

www.jasperengines.com   3 year and 75,000 mile warranty if installed by one
of their "preferred" installers.  You're local mechanic shop or dealership
may be one.  A bit pricy, but you won't beat the warranty.  I've been
through their plant.  It's amazing the improvements they make to the items
they remanufacture.

That's a lot of miles, but not excessive for a well maintained '98.  If it
were my truck and I weren't experiencing any problems I would first do a
compression check of each cylinder and compare those results to each other
and the factory specs.  If they are within factory spec and a few percent of
each other I would tend to replace what ever I could without removing the
engine from the truck.  Things like timing chain, water pump, oil pump,
distributor, and of course all belts and hoses.  I may even dig into the top
end of the engine.  Note that I don't have any experience with that engine
and I'm not an automotive technician so I don't know what kind of life to
expect out of things like the main bearings, rings, etc.