Hey, that 46AX is a HORSE!!! Good choice.

And it runs great on a 3-line tank. It really is going to be happier if one line runs from the tank to the muffler pressure connection that's already on the muffler. And that actually works great as the overflow line into the tank. If the inside of that line goes to the very top of the tank, when fuel fills the tank, it'll immediately flow out the muffler and you'll know the tank is full.

The second line would be from the clunk in the tank, out to the needle on the engine. And that line and it's little brother that goes from the needle fixture to the carb can be hooked up when you assemble the plane and you won't have to touch them again. because.....

The third line can come from the tank and go anywhere. It's tube into the tank can go anywhere in the tank you wish but just through the stopper works excellent. But the line from outside the stopper can go anywhere that's readily accessable. What you do is plug the end of it. There are things called "fuel dots" or you can go cheaper (and better) and just use a plug. If you want something that's made up already, there are some small black plastic ones sold by Tower and every hobby shop I've been in the last year. They're a buck or so and 4 to a pack. Or make your own. whatever..........

To fuel the plane, you grab the end of that third fuel line and pull the plug. Stick in your fueling line and crank away. I use a hand cranked fuel pump and slow down when I know the tank's about full and...... when fuel drips from the muffler, I stop cranking. Stick the plug back into that fuel line and you're good to go.

It's dead simple to rig.
It's dead simple to use.
It costs almost nothing.