Maybe just once a thread asking about how much an engine component can handle will properly be answered in terms of the values actually stressing them.....cylinder pressure, or in more general terms, TORQUE.
You can expect to Torque the powdered metal rods out of the engine at around 900 or so ft/lbs I would imagine if it was durated, everyday.
Considering that every powerstroke known to man peaks at 27-2800ish, that means that for most cases, this will coincide with a power output of around 440ish horsepower.
So run good tuning and keep your torque value under say, 875ft/lbs of rod breaking torque.
Now if you peaked at 2600rpm, that would likely give you just a hair under 430rwhp. But if you peaked at say, 3400rpm, you'd be rolling 566rwhp.....same load, same stress, same chance of rodding the block as the 430rwhp at 2600.
Considering that variance in power of 130 or so with the same engine stress....it should be clear that power output is not a decent judge of engine stress at all. Torque output is a much better gauge of rod life.
Diesel engine durability is a game of torque and thermal management. The rpms are so low that inertial load is a non-issue at this point.
So keep your torque down for safety, not power.