Prior owner hacked up the headlight dust caps to fit LED bulbs in. I'm looking at deep replacements and need to confirm the diameter for the low beam covers.
Also take a look at this : https://www.ranger5g.com/forum/threads/bucking-surging-epidemic.14581/
You did say the engine revs up, but this also causes hesitation on takeoff. Start around post #292.
Here's an interesting twist. She Who Must Be Obeyed was complaining about lag and stumbling in parking situations. Stealer said, "No MIL, No issue." I found this thread and talked with my SA at the next oil change. He thought about it and said it did sound reasonable and they would take a look...