I'll answer for Lou if he doesn't mind (and too late anyway ) but the end of the Uniflow line can be pretty much anywhere along the outside wall of the tank because in flight (recalling Lou's ~3G centrifugal force) the outside wall of the tank effectively is the "bottom" of the tank. This outside wall is of course where the fuel pickup will be even if it's a clunk tank. As Jim said earlier, he's used the Uniflow end anywhere from the front of the tank to nearly at the pickup. It's best to keep the end of the Uniflow line no closer than about 1/4" from the pickup to avoid the chance of air bubbles getting into the fuel pickup.

In my set ups I angle the clunk tank so the back end is further outboard than the front so the last dregs of fuel run to that outside edge of the tank to pick up every last drop. The Uniflow line is just brass tube bent to lay pretty much against the outside wall (to avoid interfering with the clunk line moving around) and back close to the clunk and halfway up the wall. That gives me a dead consistent run until maybe the last 10 seconds when it leans out for around 2 laps giving plenty of warning.