Ok, I can see where the max power calculation kicks in, the only issue is that running at 600RPM, the ratio stepdown would be massive, with 6.66 you are looking at huge pulleys or simply a 6.67:1 planetary gearbox, which wouldn't fit due to the size of the motor. I will try and look at less powereful motors, maybe some Nema 23s or shorter Nema 34 and match a gearbox to those.

Where did the 37.1Nm figure come from? at 600RPM, you only have 2.7Nm torque delivered by the motor, so over a 6.66:1 ratio, there's 18Nm on the output. Or am I missing something?

Regards,
T.