Here is my 2 drops of fuel. I have never liked the slant style tanks. They just never seemed to work for me. Now to bend the tubes, put a piece of cable through them, bend, pull cable out. The bends do not have to be perfect. I have used my fingers many times. Just curve them a little, they do not have to be an exact 90degrees. Just get them close.
Use some spit, water, window washer fluid, fuel, to lube the tubes up before you put them into the rubber stoppers.
Leave the clunk about 1/4 or so away from the bottom/end of the tank. I have had ti where the cut outs were not big enough and the engine would create enough suction to hold the clunk against the back.
I have many of these tanks.
http://www3.towerhobbies.com/cgi-bin...&I=LXD718&P=ML
I have used the stock tanks that come with ARF's for my YS .63 engine and they do work.
Dru.