I notice your car, from the picture of the engine does NOT have dual snorkel air intakes, like the later 560 motors do. I was surprised, and did not know that. Youlearn something each day.
However with the higher compression engine, less restrictive exhaust, better headers and without the skinny crossover pipe the strangled US spec engines are cursd with, a Euro 500 in a decent state of tune should have no trouble equaling the performance of a US spec 560 engine that is in stock condition.
Those Euros are how the German engineers intended them to be.
But US spec engines are what you get when you have lawyers, and Government lawyers (even worse) messing with them.........
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1991 560 SEC AMG, 199k <---- 300 hp 10:1 ECE euro HV ...
1995 E 420, 170k "The Red Plum" (sold)
2015 BMW 535i xdrive awd
Stage 1 DINAN, 6k, <----364 hp
1967 Mercury Cougar, 49k
2013 Jaguar XF, 20k <----340 hp Supercharged, All Wheel Drive
(sold)