It seems that 500 RWHP is about the limit of reasonably easily obtainable, reliable, streetable HP for either the Cummins or DMax. Much more power is available, but it goes beyond just a simple power box or programmer with a single lift pump and stock turbo.

659.3 horsepower and 1534 ft lbs of torque on #2 is an amazing accomplishment. Am anxious to hear all the details...........