I have the 35cc MVVS, it's a well made motor but a little heavy, it will pull a 15, 16 pound plane, I have mine in an ARF 82 inch Gee Bee Y, it weighs 15 pounds and it's a high-drag plane, and it flies great, I burned 89 octane last year but this year I'm going to 94 octane so I'm sure it will pull a bit better, I'm sure in a lower drag plane even at 15 pounds you will have better results,,,

with 89 octane mine will twist a Zinger 20x8 pro at 7590 tops (pretty much the same as the ZDZ & Brison 40), I tuned for flight at 7400,,,

in fairness to the ZDZ & Brison 40 the MVVS 35 will not pull a Zinger 20x10 pro, while the ZDZ and Brison will..

so if you have a large cowl like a Gee Bee then a 20x8 is the prop you will have to use, if you have a small cowl then you could twist a 18x10...

Jim