First thing I would do is check to see if you are getting fuel to the engine.

Then the second thing is...

Get a Multimeter.

Then I would remove the DSII harness from the truck, unwrap the black wrap around the wires, and use the multimeter set to OHMs and check the continuity of each wire in turn between the connectors. Check for cracks in the insulation, burn marks etc... repair as needed, then rewrap the harness like original, with black electrical tape. This will make sure the DSII harness is in good shape.

Then plug the harness back in, then with the ignition switch in the run position, check to see that you are getting power at the coil. Red/Lt Green Wire. With the ballast resistor in line voltage will drop to 6-8 volts in run, and you will get a full 12 volts in start.

If so then check the coils primary and secondary resistance using the multimeter.

Primary Coil Resistance
1. Unplug the coil.
2: Measure the primary resistance between the Batt and Tach test terminals. 0.8 to 1.6 ohms. If out of spec, replace coil.

Secondary Coil Resistance.
1: Unplug Coil.
2: Measure the secondary resistance between the Batt and center terminal of the coil. 7,700 to 10,500 ohms. If not in spec, replace the coil.

Stator check. (Magnetic pickup)

1: Unplug the distributor harness. Inspect for damage etc...
2: Check the Stator resistance between the Purple and Orange wires. 400, to 1,000 ohms.
3: Now check the Isolation resistance. Attach one lead to distributor base, and the other to the Purple wire, and orange wires in turn. one at a time.
4: If the stator resistance is less or more than the specified resistance, and/or the stator isolation resistance is less than 70,000 ohms, replace the stator.

Have your ignition module checked at a local auto supply store.

That should check everything except the cap and rotor, and plug wires.

One thing that bothers me is with your start bypass button, the coil, and ignition module will not be placed in the proper start mode for starting, because you are not turning the key to start. You need to fix this system as well.

EDIT: Perhaps you have a bad or misadjusted Clutch switch. The clutch switch keeps the truck from being started unless the clutch is fully depressed to the floor. 1984 and newer.

And as always, Good luck.