250-1 Bosch 750.
Minimum size gear on the motor-axle. Mod1 Z 18. Or Mod 1.5 Z14.

4 stages. Each time stepping up the mod.

Z18-Z72

Mod 1 mod 1.25 mod 1.5 and mod 2

End result is the wopping 2772 Nm stall torque...