I've got a G23 mounted inverted in my 1/4 scale biplane, & oriented the tallest part of the stack UP, only reason being that way it matched the curve of the round cowling. Works great, looks like it "belongs" there, & is easy to put my hand over for drawing fuel into the carb. From the threads I've read, I'm not convinced that the orientation is a big deal; the fact that a velocity stack is ON the carb will help in itself. Just my $0.02 worth. -Daniel