The Saito should be about perfect for that Stearman. You still may have to add some nose weight. Any Bipe that had a round motor is going to be short coupled, they were designed that way to compensate for the very heavy weight of those round engines they used. Most of the 17s or Supers I have seen have the 1.20 OS up front, pretty much required due to the added drag of the Bipe. Anything smaller and your going to be walking around saying things starting with, I wish in front of them.