Phil,

It's your choice, however, since the ends of the clunks I use are slotted and beveled 45 degrees, I prefer the aluminum tube method. This method provides greater rigidity and points the clunk at roughly 30 - 45 degrees from the stopper vs a clunk affixed to roughly 5 inches of flexible fuel tubing, that may tend to lie sideways on the bottom of a large fuel tank. The aluminum tube method, if properly constructed, should provide you with maximum quantity of available fuel in the tank.

Steve