I have been wanting to replace the 2 Magnum .52fs on mine with the Saito .40. I have one in a 1/6th scale Super Cub and it is a great little engine. It hasn't quit in the air in the 6 years that I have had it and it is quite light and powerful. I would think an 8X6 3 blade would work well with it, although I havn't tried it.
Ben