Folks
I recently purchased a 1987 Ranger 4x4 for my wife with the 2.9 engine. I'm interested in what spare parts other than belts and spark plugs you recommend to have on board for field repairs?

 

I myself don't carry spare parts. All I have is Jumper cables, 1 Qt oil, 1 Gallon pre-mixed coolant

If you're worried about losing a belt or heater/radiator hose on the road, just replace them now.
Spark plugs are going to be broken or not gapped properly by the time you need them. Just put new plugs, wires, cap, rotor in now.

Where do you draw the line for what to carry, Alternator, Water pump, U-joints, Wheel bearings, Wheel cylinders for the brakes, Brake pads, Brake calipers, Ignition control Module, Engine control Module, Starter, Power steering pump....................

 

I like to have a spare tire.

 

This question can be answered a few different ways depending on what you are doing.

Just ordinary driving around town.
Spare tire is all you need

Going on long distance off road trip away from towns and towing services then you will need some important stuff
Duct tape - lots of it.
A spool of rope
1 to 2 Qs of Oil.
Maybe Some coolant.
A tool set that can cover what you need to limp back to town potentially.
Recovery gear.
Another vehicle (Best to travel in pairs then stranded alone).