You should re check with the motor manufacure. For example ABB for their Aluminium 132 frame motor state 2 x M25, and the 180 frame 2 X M40, yet for their cast iron frame the 132 frame has 2 x M32, and the 180 is the same with 2 x M40.
Are the motors new, has somebody re drilled the 180 frame to accept bigger cables??