I am pretty sure it is a slim line because its a tight fit to get the tank inthe wing. My lines are as follows
My fuel clunk went to the fuel filter,
I used my vent to go to check valvle,
I opened up the middle line in tank and ran a smaller piece of fuel tubing out so I can use it for filling.
To fill I unplug my middle line (fill line) and undo it from the check valve to fill up. When I am don't I have to take the line off of the fuel filter then suck the fuel out. I used the 3rd line so I won't have to find the line with the fuel filter on the bottom of the plane, except when i had to suck the fuel out.

Hope this helps. Keep me posted.