Drove it for the first time in a week. I think I've identified the engine noise as piston slap. Not sure what I intend to do about it. Probably let it run its course. If she pops the engine, I'll rebuild it if possible or source an engine to rebuild, then rebuild that. I doubt it will- a little piston slap never killed a 4.0. The GMC's been running with piston slap for thousands of miles. Even the Jeep's had it as long as I've owned her.
I need some paper, dawg.
1998 Grand Cherokee 5.9 Limited
2016 Wrangler Unlimited Sahara Edition
Signature rules are dumb