Update, wow I had no idea I dealt with that noise for this long haha the Jeep is not a daily driver.
Found it, the motor mounts and trans mounts had gotten so bad that under power the yoke could move and hit the plastic bracket that holds the wiring for the rear 02 sensor. There was pretty much zero evidence that this ever happened because it didn't do it often and when it did it was just a few revolutions of the yoke before it quit. I still have to replace the passenger side motor mount but a new trans and drivers mount fixed the problem. The passenger side mount is really ok but I figured I should replace it to match the others.
New tires, quiter muffler, new trans and engine mounts and this thing is enjoyable to drive again.
68 Barracuda Formula S 340