Random timing rattle after some cruise time

I am working with two 2005 Dodge Ram Cummins, both having the same issue, but quite different builds. After cruising for 15-30 minutes above 50 mph, I get a timing rattle, or loud dieseling sound, rolling in. If I floor the throttle, the sound is much louder, and I gain no power. I only do this for a split second, because it feels like the timing is suddenly advanced far enough to cause detonation, and I don't want to blow the motor... this never happens while under heavy load/boost, just cruising, with or without a load, and 50 mph on up. My rail pressure will peak on one truck, and increase by 20% on the other. I have replaced the FCA on one truck with 5 different ones (modded, new, two used, then new 6.7), with no changes. On a road trip, the timing rattle will roll in every 5-10 minutes, and will go away with engaging the clutch and allowing the engine to come to an idle, then all is normal. Occasionally it will do yhe same thing at idle while warming up, rattle with depression of the accelerator, then normal after idling down again. Completely normal around town and short jaunts, like stop lights every couple miles, 60 mph in between.

I have tried data logging, but my vcm scanner only gives me a handful of basic parameters, no desired parameters, and I have more info on the Smarty Touch monitor. I also never had these issues with Smarty S06 Pod, either truck.

Anyone have experience with this situation?

Thanks in advance!