Gearing is the way MB gets away with propelling a 3500lb auto with a 160 cubic inch motor and still call it a sportscar.
What you get down low can only be replaced up high with another gear. Since the engine has a 6000 redline (or so), you still should be able to go top speed which I would guess is almost 130.
Bosch Master, ASE Master, L1
33 years MB technician