Well I tried to measure the mounts, but it is difficult, as the shape of the mount is somewhat affected by whether the motor is bolted into or not.

As best I can tell, the dimensions of the bolt pattern are

6 5/32 X 2 3/32 inches. The longer dimension is across the turbine, in other words parallel to the wingspan.

This is very rough and will likely require slotting of the holes, so be forewarned!