2 exchange-standard references match the MERCEDES S-Class (V221) S 63 571 hp (420 kW petrol). Output is the deciding criterion: a part meant for another output of the same displacement will not fit.
On the MERCEDES S-Class (V221) S 63 571 hp, the code stamped on the part remains the safest matching criterion.
Other engines of the MERCEDES S-Class (V221): S 63 544 hp, 500 435 hp, 300 Turbo-D 177 hp. If the code stamped on your part is legible, search by reference remains the safest route. 24-month warranty.