Intermittent rough idle, usually when warm

[Heresy]

An update of sorts. I texted the guy yesterday about what he sold me. He is a diesel mechanic who basically used the truck until he found something better suited to his needs then sold said lesser truck to me. Anyway, he confirmed that he replaced the distributor cap and rotor but none of the associated wiring or interconnects. The O2 sensors probably should be replaced, and they are cheap and easy enough swap out. This coming weekend I hope to go through the normal maintenance items to make sure the idle isn’t due to something too painfully obvious.