Thanks Mike,
I have both Delta and Aesthesis set- up with GT33s and both set-ups use 1 1/4" stand offs. But their firewall to washer lengths are different. Aesthesis was originally intended to be powered with a ZDZ40 which is about 3/4" longer than the OS. So the mount is much thicker than normal to compensate.
One other thing, I always cut a hole in the center of the firewalls to make space for the carb. Anyway, the length on Delta will be more typical of most set-ups. It is exactly 7". The mount is exactly 1" thick and the stand offs end 6" from the washer. If your set-up doesn't quite have the room, consider a shorter stand off but more carb will need to be tucked inside the soft mount
The OS has very deep fins and cools well but I duct cooling ram air directly over them anyway. Even in narrow pattern fuses, ducting eliminates any overheating worries. Although I've not flown in 110 degrees, more like 95, I think it will work well.