I am of the opinion that the DuraMax block in the picture failed ,not because of a weakness in the block , but as a secondary event, to a rod failure. The rods in this motor are fairly strong to the failure point , the failure point is also related to the tune up.
As in any other form of motor sports when you break a part, you do a post failure analysis and extrapolate the primary cause of the failure and any other contributing factors. The primary cause of DuraMax failures are rods integrity and crankshaft flex. These failures become more apparent and exaggerated in lower RPM from over unit loading of these parts . as RPM goes up the ability of the engine to produce these loads need to cause failure of parts goes down . and from this we learn that if we can raise the RPM that we make peak power we can make these parts live at a higher HP level . this goes hand in hand with making more usable HP .
In the motor sports engineering community there is only one way to produce more useable power , whether its in a Indy car , NHRA stocker or a diesel drag racing engine , that is to burn more fuel with the proper corresponding amount of air. There are two ways to achieve this , first make the physically motor bigger , or trick it in to thinking its bigger . that is make it have more actual displacement or make it think its bigger by artificially raising the pressure in the intake track above atmospheric. So there we have it , more CID or more boost.
Second is to make it have more power pulses , there by burning more air and fuel or in simple terms turn it more RPMs and this in my opinion is the only answer to making power and not breaking parts.
Now how to achieve this ,
Improve cylinder fill , this is achieved with better cylinder head intake track , and camshaft design. If you have less restriction thru the intake track , and the cam works in conjunction with the heads air flow map. then you turbo can move more CFM of air in the sweet spot on the turbo’s map. Now that you have air flow you can rev the motor up , creating more power pulses per minute and thereby making more total power. The RPM this is achieved is well over the torque peak and provides less stress of the weak links in the motor.
The DuraMax has many advantage over the other motors such as big journal cam cores , 60 mm and very stable valve train. This allows the valve to be controlled in a more precise way achieving maximum window to flow air through , and not have long seat timing that hinders cylinder pressure issues the heads on the DuraMax are in max ported form approximately 75% better in air flow then the Cummins aside from being a 125 lbs lighter.
Attention: TDR Forum Junkies 
#ad
..... and it was a single turbo, ..... 900 TQ maybe,
