Today, I began by checking the spark plugs. I pulled them all out, inspected them, wiped them down with a shop towel, looked 'em over again, and then cleaned 'em up using a wire brush and some carb cleaner. I did not see any color difference on any of them. See pictures at the end.
Another thing I noticed was what I believe is called the fast idle cam was quite stiff and would get stuck when being pushed back up by hand. With some far more than normal effort, it would finally go all the way up. I am not sure if that was a culprit in any way. See picture below.
My neighbor suggested checked out the ignition control module and the coil. I took them over to Autozone and had the ICM inspected. It passed twice. I noticed that there was no heat-sink compound beneath the ICM and this Autozone, it turns out, doesn't carry it. The employee helping me suggested using di-eletric grease. I wasn't able to get the coil tested because no one knew how.
I came home and looked up how to test the coil and cam across this thread: "Testing HEI Coil/Module"
. Doc Vette (RIP)
provided the instruction on how to test out the coil in cap. The problem was, none of my two voltmeters were resetting to zero, and kept showing "1"
I then took the coil to Autozone and borrowed their voltmeter. The primary kept showing about 0.5 ohms. I could not get a reading for the secondary. However, when I took one prong to the rotor button and the other prong to the ground pin, which gave a reading of about 12.39 ohms. The employee looked up my info and it turned out the the coil was still under warranty. He swapped it out for a new one (Duralast brand)
, which I installed in the cap on the spot and then tested it out. The results were the same: about 0.5 ohms for primary, no reading for the secondary, and about 12.39 ohms when connected to the rotor button and the ground. I do not know what to make of this information and have decided to order another coil, probably from Summit, and return the Duralast one under warranty. Any recommendations on brands are very much welcome.
I came home, and reinstalled everything. The truck would crank but would not start. I figured the new coil was bad. However, I had struggled with plugging the battery wire to the coil, and decided to check to see if I had mixed up the battery and tachometer wires. After looking at pictures from a previous repair, it turned out I had mixed up the wires. I then swapped the wires into their correct places.
The truck then started up perfectly. i let it warm up for a few minutes and then took it for a spin. The transmission shifted smoothly. No hesitation, sputtering or bogging.
While I am glad the truck is back up and running, I still am not sure what exactly went wrong.
Thank you Crussel and Augusto for the help!