Turn the headlights on, and check their brightness. If the lights are dim or weaker than normal; the battery should be charged overnight with a battery charger that has a 6 amp or greater output. Then put the battery back in the truck, and connect the cables to the proper terminals (serious damage can be done to the electrical system if the battery cable connections are reversed). Turn on the headlights and check their brightness again. If the headlights are still dim or look weak; the battery should be replaced.
Once a strong battery is in the truck; it can start more easily. If it still does not start; take the distributor cap off, and watch the distributor rotor while running the starter. If the rotor does not turn steadily and smoothly while the starter runs; the timing chain has broken, and must be replaced.
If the distributor rotor turns while the starter runs; buy a can of engine starting fluid, disconnect the large air duct hose from the throttle body, prop the throttle butterfly open, and spray a 2 second burst of starting fluid into the throttle body air inlet. Then quickly release the throttle butterfly, slip the intake air duct back in place (don't bother to tighten the hose clamp at this time), and try to start the motor. If it fires briefly or starts and soon stalls; the engine is not getting enough fuel. This can be caused by a bad fuel pump, or a bad fuel pump relay, or by a bad intake air temperature sensor. I would replace the air temperature sensor first; then replace the fuel pump relay; and last replace the fuel pump.
But if starting fluid does not make the engine start or even fire; this is not a fuel supply problem. In that case, disconnect the cable that comes from the ignition coil from the center terminal of the distributor cap; and clamp, tape, or support the end of this cable with a wooden clothespin or a block of wood so it is 1/4 inch from the engine block; while someone cranks the starter. There is a risk of electrical shock if you hold the cable by hand. There should be a stream of sparks from the cable end to the engine block while the starter runs. If there are no sparks from the coil wire when the starter cranks the engine; the coil or the coil wire, or the crankshaft position sensor should be replaced.
If there are sparks from the cable while the starter runs; put the cable end back in the center terminal of the distributor cap, and disconnect one of the spark plug wires from a spark plug. Either slide the rubber boot back on the plug wire to expose the metal connector; or insert a bolt or paper clip so it fits firmly into the boot, and support the wire so that the metal connector or end of the paper clip is about 1/4 inch from the engine block. Crank the starter and watch for sparks from the wire. If there are sparks from the wire; install a new set of spark plugs, and see if that makes the motor start.
If there are no sparks from the plug wire; replace the distributor cap and rotor, the plug wires, and the spark plugs. Be sure that the cap fits on correctly and the plug wires are in the right positions on the distributor cap. This should get the motor running.