Mr. Cline recommends letting the regulator hang, vibration could adversely affect it. That said, on a UCD, its a challenge to let it hang and keep the fuel line from the regulator to the carb short <and> keep the regulator at carb level. There isnt a lot of room behind the carb to the firewall, and no room beside the carb to the cowl. I dont have pics, and honestly I'm too lazy to pull the cowl to take them... I'll describe what I did, it works.
I used the GP super fueler- when it sticks I'll replace it with a fuel dot - and the stock fuel tank in a 2 line config. From the tank, run the fuel supply line to the fueler (or a dot). From there, to the "in" side of the regulator. On the "out" side of the regulator, I ran a 2 inch line to the carb, and let the regulator hang directly below the carb, wrapped in thin foam to prevent any damage from rubbing against the crankcase or intake pipe. On the vent side, I ran a short line from the muffler tap to the one way valve, and let the one way sit outside the cowl. Then a 2 inch line into the cowl to the "T" fitting. One side of the "T" goes to the tank vent, and a 3" line from the "T" straight down to exit out the bottom of the cowl - this line gets plugged and is unplugged only for refuel, and to relieve pressure.
The only drawback to this setup is the initial run of the day, the carb has to be primed as the regulator sits too low - I do this by unscrewing the needle valve and pumping a few drops through the needle valve fitting - after the initial run, I dont have any problems whatsoever, and the engine flips right over with no priming required.

hope this helps...