G26 is perfect for a 1/4 scale Cub. I can see people object to the smell of gasoline (me included), but how is gasoline any riskier to handle and store than methanol? Both are just as volatile and flammable. I don't think their flash points are much far off each other. I've known some racers who regard alcohol as more dangerous because the faint blue flame is practically invisible during the day.

Ray, most folks mount their gasser inverted. Unlike glow engines, gas ignition engines don't mind being mounted inverted. In fact, some may argue they actually run better that way. With that narrow J-3 cowl, you pretty much have to mount the G-26 inverted. Slimline makes a very nice wrap-around muffler for an inverted G26/G23. It's a little pricey, but will probably allow you not to have to butcher up the cowl. I believe MAN used this exact combo when they tested the H9 1/4 Super Cub.

Lightweight glow engines do better than gasoline engine on 1/4 scale aerobatic planes (~ 72" wing and ~ 10-12lbs) like CAP 232, Edge 540, etc. On these 1/4 Cub floaters, gasoline engine work very well.

4stroke glow boxer twins are great, too, if you don't mind the price tag.