Engine Knock at high rpm and load, fine at idle

Fixed one truck now on to another. Thought I would try this before I pull my motor. I have an earl 99 7.3 manual trans. with 230K miles on it. It has a nasty knock that shows itself at heavy loads. You can feel it in the floorboards Ive been chasing it for a few years. This engine has never liked to rev like other Powerstrokes, has always been noisy, even when new. I never new I had a problem until a drove a buddy's and it was so much quieter. Over the last 20K miles the knock has been moving lower in the rpm range. Starts at around 2200rpm. It is a lot worse when the engine is cold. Taking the tune out makes it a lot quieter but it is still there. So far all I have done to the truck has made no difference in the knocking. If I really get on the go pedal and force it to 2800 the power drops off and it smokes sporadically ( not a steady stream but also not with the beat of any cylinder)
Reman injectors
-Adrenaline HPOP
-Tried different ECU and IDM with and without tune
-Buzz and contribution tests come up with nothing.
-All new sensors.
-Very little blowby, barely wisps out of the oil filler.
-Regulated return kit ( fuel flows thru the heads)
-New stock fuel pump and filters (no fuel pressure drop at heavy load)
-Never any metal when I change the oil
-No bent push rods

Any thoughts would be appreciated, Im thinking either a rod bearing or wrist pin. It just throws me that the engine sounds fine at idle when hot and that it has progressed so slowly over so many miles.