The pipe length looks about right, but is it the right volume? Loose the deflector, at least for now. And loose the spinner, you can let the engine chuck it at a later date, just kidding, I don't know how well it's made or balanced it is but try it at another time, any vibration can suck up a lot of power. If the spinner's back plate is skeletonized, forget about it. 30% nitro would be better but not mandatory, I have ran them on FAI fuel with surprising results, but you need to take out all or some shims. You need to make sure the piston has some head clearance! 22% oil is a good idea, at least through the set up and break in time. I would add some castor to what you have to get it there. This link will help calculate mix:
http://www.nitrorc.com/default2.asp?...orc.com/fuelws
The 11X8 Zinger cut down is safer than a cut down 10X10 APC! At 10X8, that prop is still a lot of load, much more than a 9x10 APC carbon clone. For one thing, that wood prop is a heck of a lot thicker and at those speeds the disk area is more important than pitch when it comes to static engine loading. Think thin prop and small disk area. Thin it and start making the prop smaller in 1/8" increments. For what you have done, your engine is doing very well.