This is my first post here so if it belongs somewhere else please let me know.

I just finished replacing the distributor cap, rotor and spark plug wires on my truck today, it's a 5.9L 4WD. I started by marking the cables on the cap to limit the screw up potential; changed the cap and rotor, then plugged the old cables back where they belonged. I then installed the new cables one at the time, and when I was done I double checked just to make sure, and, perhaps not surprisingly, two of the cables (5 and 7) were swapped.

Now, given that cylinders 5 and 7 are

• next to each other physically
• next to each other in the firing order and
• next to each other on the distributor cap

is it possible that they had been swapped all along without significant malfunctions? I bought the truck used and only put a couple of thousand miles on it. I even thought about swapping them on purpose but I don't want to push my luck.

Sorry for the long explanation but I figured more details the better. Thanks for your help.

 

The firing order is 1-8-4-3-6-5-7-2 clockwise rotation.
Cylinders are numbered like this.
Pass side 2-4-6-8 front to rear.
Driver side 1-3-5-7 front to rear.

So 5 and 7 are adjacent to each other on the cap.

Could have gone in tech section.