Hi Paul
11x11 would be the best of those, it's not a sreamer 8mm intake and port timing designed for torque, best static rpm with the stock pipe is about 10800/11000 rpm on FAI fuel, I'm going to try some head shims and 15% nitro to see If I can squeeze some more out of it but it didn't like it when I tried 10% on the bench.
When I was experimenting with props on my Speeda/ASP 91ABC/Macs pipe combo I prefered the overall perfomance with the 12'' prop over the 11'', the ASP likes to rev more than the MVVS so I found 12700/13000 static with either the an 11x10 or 12x8 it made the best power but the 12x8 flew better, level flight straightline speed was very similar but vertical on 12x8 was far superior, about the only the place the 11x10 was noticebly faster was the bottom of a full throttle split s where it was really rockin.
Back in the non piped 61 days we couldn't run a 12'' prop because you could only pull 6'' pitch and keep the engine in its power range so it was way to slow so 11x7 or 8's ruled, my initial instinct when I got back into the hobby playing with these things was straight to 11'' props and pull more pitch with the more powerfull modern engines but I'm shifting my thinking to 12'' now and adjust the pitch to the particular airframe/engine characteristics.
I think the Magic will perform really well with the MVVS turning the 12x10 at 11000 on the ground just won't sound like I like em to sound.
I have a Webra 91 P5 for my next Speeda and have had that turning a 12x8 at 14200 on FAI fuel, I think thats pretty close to as strong as a Jett 90 so that will definetly sound right!
I can't believe how many pattern ships I have to build with all those Don fuselages and that Galaxy arrived fron Italy as well, phew!
Cheers
Greg