The first thing that comes to mind is to check the timing chain.  This is
relatively easy to do by removing a valve cover, and observing the amount of
slack by turning the crankshaft pulley with a breaker bar/socket, and seeing
how much play there is before a valve moves (roll the engine clockwise until
a valve [doesn't matter which one] moves half-way down, then see how much
you cal roll it back before the valve starts moving back up).  A dial
indicator is useful here, to know exactly when the valve moves.  Any more
than about 5 degrees of rotation before valve movement would indicate a worn
chain.

Over 100K would make me wary of the water pump, as well.  I might change
that as a preventive measure, and would definitely change it if it turned
out the timing chain was worn.

Beyond that, it would be more about what I would bring with me...  basic
things like serp. belt, oil, tranny fluid, coolant [water is fine], hose
repair kit, some JB Weld (lots of potential for fixing things here...  holes
in radiators, oil pans, tranny pans, diff covers, etc.).  I would also pick
up a spare front wheel bearing.  It'll run you a couple of hundred dollars,
but it will be money well spent, because eventually you'll need to replace
one, or both, front hub bearings.  As long as you have a jack and basic
tools with you (including a hammer, and 12-point sockets), you can change
one of these if the need arises.

Some other things to throw in your emergency box...  pick up some master
cylinder plugs.  With one of those, and a bottle of brake fluid, you can
survive a broken brake line, by blocking off the broken line, and using just
the remaining brakes (front or rear).  A plug kit, some Fix-a-Flat, and a
small 12V compressor will deal with most tire damage.

As Tom said, timing chain is a serious concern. Something to
check.

What comes to mind to me, are both the "what to pack" issues, and
"how to go about the trip".

Tires. Being 100 miles from the paved, I'd want a spare wheel.
Tire plug kit, Fix a Flat, and the lighter socket power air
compressor. Tires are a serious concern. Farmer jack might be
useful, in addition to the scissors jack. Breaker bar and impact
socket set.

The other concern which came to mind is getting stuck. Definitely
have a come-along winch, and chain and rope. I've gotten my truck
stuck in the mud one time, where I had a tree in the right
dirction, but no come along tool. That was embarassing. If
possible, travel with another group, and take turns going ahead.

Communication. I'd bring the cell phone, even if you think you
won't be in service area. Sometimes you can get a signal from a
hill top, or top of a tree. CB and FRS are also good for short
range comms. Satelite phone, I've never used one but hear they
are expensive but worth it.

Fluids. Gasoline comes to mind. Please buy good gasoline, such as
Mobil or Exxon. Nevermind the save 2 cents a galon crap gasoline.
And a couple bottles of alcohol drygas. Water, both for you to
drink and also for the vehicle cooling system. Oil, and
transmission fluid. In a pinch, you can use Dexron II in place of
motor oil to get you out of a spot. Dexron II also used as
steering fluid. Brake fluid. Couple cans of ether starting spray.

Plan on maybe having to spend a night in a tent. Unless that's
already part of the plans. Tent, and multiple ways to light and
kindle a camp fire. Lighter, matches flint.

First aid kit. And medications you usually take, plus the ones
you don't want to need (pack the pain pills you got after your
last dentist apointment).

I'd suggest to post this question to alt.survival and
misc.survivalism and rec.backcountry where you will get different
(and possibly better) advice than what I've written.

Generally, the part that breaks is the one you left home.

There's a ton of good advice written on what to bring. Here's a couple of
more from my beach playing day's. A couple of 2x12's a foot long to put the
jack on, in case your in mud or sand. Also some other blocking just in case.
If need be you can always burn it. A air tank, a compressor is good but
sometimes not fast enough to catch the repaired area of a tire. The ones
where ya rip the sidewall a bit on a rock and have a handful of plugs and
slime in the tire. A hunk of that blue plastic 9x12, folds up small and
gives you something to lie on, keeps you dry. Also make's a stretcher for
worse case situations.