You can mount the carb anywhere you want as long as the length of pipe from carb to intake is the same. The real question is, how would you secure the carb to the motor then?
I am back to working on my Cub and discovered the fuel tank is way too high(Following what I mentioned above with tank relation). Bummer, to lower the tank to fit would be a major undertaking since the plane is nearly finished, all construction is done, just a matter of putting the windows, door and radio in.
Back to refitting a smaller engine now since it is setup for a side mount. When mounted sideways the tank is perfectly aligned. Problem is the 100 GK is WAY too large for a side mount, would have to fly it without a cowl. I will give it a once over to see what it takes to lower the tank floor, but IIRC it is locked in to the sides and firewall.
Oh if only I could afford another FG-11 or 14.