The E63 AMG is a 2013 rear wheel drive model. This car has a tune from Renntech along with RADO downpipes said to be good for around the 630 wheel horsepower range. Torque is in the turbo M157's favor with 735 lb-ft at the wheels. The M159 by contrast has 463 lb-ft at the wheels which is a very large difference on paper. Nobody will deny turbocharged motors are capable of big torque numbers.
That said, the SLS Black Series features tighter gearing and a much higher redline at 8000 rpm. It's a motor with a definite breathing advantage at higher revs.
Power and torque are in the E63's favor (at a lower rpm) but the SLS Black Series is roughly 600 pounds lighter. The SLS also has a dual clutch transmission whereas the E63 is using the MCT wet-clutch automatic.
So what happens? A great race is what happens. The SLS gets a slight lead thanks to its shift speed advantage and manages to pull in the lower gears. Up top once the cars spend more time in gear the E63 is able to inch back but not enough to win the race. It's close at the markers with the Black Series slightly ahead.
Simply a great run from two great AMG motors that employ different, yet very effective, strategies.