Plugs swapped out for the OE Bosch Supers. Car ran flawless for about 20 min. then dropped back into the missing cycle again. Now I'm dreading that something got disturbed with the wiring harness throughout the process of replacing the plugs and wires

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As of now, plan A is to double check all of the vacuum lines to ensure that nothing is screwy there. If that checks out then it's time to inspect the wiring harness in further detail. I'm planning on posting pictures of the areas of concern (wiring harness exposure areas in the engine compartment) to see if anyone can help to provide me with some insight to the problem. (I've read all of the posts so I know which areas to closely inspect)
With the car's history of roasting in the southern Texas heat for 13 years, I wouldn't be surprised if this was the cause of my problems.
Definitely keeping everyone posted...