I've gotten to where I use a 3-line setup almost exclusively, eliminating alot of the BS of fuelers, removing carb lines, pinching carb lines, etc...

For three lines I setup a vent tube bent to point toward the top of the tank. I setup up the clunk line as usual. I setup up the fill line like an extra clunk line, but do not use a clunk on it. I bend the tube behind the stopper on the fill line toward the bottom of the tank at about 45 degrees and put a peice of fuel tubing on it that reaches the rear of the tank. The slight bend in the fill tube biases the fill fuel tubing to the bottom of the tank and ensure that I will always completely empty the tank. The stock CapX tank has a fill/empty nipple molded in that could be opened and used, but you would have to make sure the plane is nose down to empty it completley. The stock CapX tank also has a nicley placed vent nipple. So here's how I'd do it if i were using the stock tank. Use the two open holes in the stopper for the clunk and fill/empty lines and use the molded vent nipple for the vent.

Sorry I rambled a litte, hope it's helpful...

Richard