As much as you would like to find issue,
I would like to also know what is causing it.

If it's the tune, I'll take the blame for it.

Just looked at the last file that was flashed into truck, 12 deg timing

 

Has it been same cam in all motors?
Have all main bearing and rod bearing been inspected?
I had metioned thrust being and issue, same trnas and conveter on all motors?

 

Forgot to raise pressure on hptuners 00z71? Jk.

 

detonation may open up the ring lands on the upper compression ring, so check the ring-to-land side clearance with a feeler gauge. If less than .001" or more than .002", thats suspect. It's not just a matter of does the piston looked blasted clean, you've got to measure stuff.

Any tiny ***** of aluminum stuck to the sparkplug insulators?

Detonation will really show up as damage to the upper half of the rod bearing inserts. There will be a dime or nickel size worn spot right in the center of the upper half. The inserts may fall out of the rod when you pull it off the crank. Check all the rod inserts, not just the spun ones.

Did you do any wideband tuning? It could be going lean. Killing the same rod bearings every time in different motors could indicate a fuel distribution problem. Did you re-use the intake/injectors, etc every time?

The only other thing would be a bad oil seal in the turbo. Oil in the intake air is bad, it pollutes the intake charge air and aggravates a motor's tendency to detonate.

 

Like you metioned, injectors no matching...
Truck was taken to me smoking issue, I found bad turbo bearing and oil on intake. Turbo was rebuilt, but this was on the current engine