csdilley, I realize that, but it appears that mounting it right-side up will put the crankshaft centerline higher than if it was inverted.

I don't see any reason to run without the cowl. I have not had any overheating issues, just make the cut-out in the front generous, and cut a good hole in the bottom for the air to exit. And it looks so much better with the cowl on...

FWIW, I have had zero problems with mine inverted. I just fuel right before I know I'm going to fly and leave the probe in the quick-fuel valve till the last second. Then I make sure to pump out any fuel that may be left in the tank afterwards.

EDIT: looking at that pic of the UCD without the cowl, it appears that the crank centerline is very close to where it would be if the engine was inverted. I took a closer look at mine, and the mounting beams are not centered up and down. So I assume that that will even it out if you flip the motor mount over.