I have the MVVS 35 gasser with the inverted side muffler, it will swing a Zinger 20x8 pro peaked out at 7690, tuned for flight at 7400 and the plug was glossy black, I now have a 3W 20x8, I have not tried yet, but the 3W has a little bit less cord width on the blades so I may get up to 7600 tuned for flight,,,

I tried a 3W 20x10 and it was just to much prop for this motor "without a tuned pipe", it peaked out at 5900, but tuned for flight at 5500 it over-heated on the climb-outs, and it didn't climb-out as good as it did with the Zinger 20x8 pro,,,

I have been using Bell Ray H1R at 40 to 1 with 89 octane, but it's a higher compression motor than some of the other brands so this year I'm going to try 94 octane, that will give me a little more pull too..

Jim