How's the old saying go? There's no substitute for C.C.'s.
If you want more power buy a car with more power or a bigger engine.
If you want a car to drive like a sports car - buy a sports car.
M.B. designs their cars as a whole. If you modify one part, you must modify all the parts to suit. e.g. The 260e uses a different transmission to the 300e - why is this so?