Thanks for the reply...

The reduction drive will ultimately be used for a 1:5 scale Hawker Typhoon... Thats the reason for the 33,6in dia prop, as this is the scale size.
I´m well aware of the problem of a stalled prop. My software suggests that up to a speed of 33mph the prop will be partially stalled, and that the prop will stop producing thrust at 75mph.
What I´m most concerned about is that the prop, when being stalled, will not even make the plane move... I guess that it will be like starting your car in 5th gear....uphill...
But on the other hand... When the plane starts accelerating, the thrust will increase steadily during the takeoff, as the prop gets out of stalled condition and should provide good speed/thrust just before takeoff when it´s most needed. If the 33mph the software suggests is accurate, it would not be much of a problem, as I don´t think I´l will be able to keep the plane flying at that speed anyway.
I have also thought about reducing the pitch slightly and run the engine at higher rpm. With the current setup the engine will be spinning at 8K on the ground, but originally being a chainsaw engine I don´t think that it will kill the engine going 10K instead, which is where it will develop the most power.
The complete model will probably weigh somewhere between 33-40lbs.