Quick Fix
I got under the dash to take a look and found this temporary solution:
The switch slides on the shaft that goes from the clutch pedal down to the firewall. You can actually start the truck by (make sure it's in neutral!!) getting under the dash and holding the key in the start position with one hand, then sliding the switch upwards on the shaft a few inches.
There is a notch in the switch housing where it seats on the firewall end of the shaft. If you rotate the switch clockwise about 1/8 of a turn (push the wiring connector that goes to it to the left), and then let the switch slide back down, the notch in the switch housing will not line up with the peg that goes into the notch and the switch will remain unseated by about 1/4" . In this position the switch will make better contact when the clutch pedal is depressed and the truck will start right up. You can zip tie the wiring harness from the switch to the main wiring harness just above and to the left of it if you want to be sure to keep the switch in it's new position.