I would consider using a 2 X 2 Manifold that will allow for mounting the generator in the stock location. If you feel you need more carburetion, you can always use two Stromberg 48s which are readly available and will flow a lot more air then 97s. This way there would be no issues with a fan and I can not feel a street driven 21 stud would ever need more carburetion then two 48s.
Again, this is just my opinion,
Chris