I don't know for sure, but information suggests that there are some SW1000 units with the D32 main generator, which is an advantage since it would eliminate having to change motor connections. If the sequence and timing isn't just right, changing motor connections can lead to fireworks, so it has to be correctly maintained.

EMD also has a smaller version of the AR10 which is an AR6. So far, the only application I have seen is for around 1500 hp for export use. The amperage rating is quite a bit lower, so it couldn't supply the drag rating of D77 motors. I think they are using the AR6 primarily with narrow gauge traction motors, which due to their smaller size have a substantially lower rating.

As far as traction motor ventilation - most of the industrial GE's using GE733, 741, 747, 763 motors are self ventilating - there is a "fan" built onto the armature shaft for traction motor cooling. Most GE 70T use GE748 motors which are force ventilated. I think the EMD SW-1 and maybe the SW600 might not be force ventilated, but I don't know if there is a version of the traction motor that is self ventilating or they just let natural air flow keep them cool. Otherwise early SW's have two mechanical blowers, one under the cab and one over the front truck. The GE 70T, EMD's with AAR or Flexicoil trucks do not have the typical rubber boots to duct cooling air between the bottom of the frame and top of the motor - instead, the cooling air is ducted through an open centerplate into a hollow bolster, where rubber boots connect the bolster to the motors on a horizontal plane.