What a coincidence. I just helped a guy break in a Saito 56 engine!
You'll want to use a fueling valve, between the carb and fuel tank pickup.
http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXD745&P=MLOtherwise, you can use a 3 line tank, with the third line being the fill line.
Hope this helps!
Chuck