I have many times... your gonna have to use the 2" grommet
from your tank or buy a new one..Auto One sells new ones..
depending on the alum thickness you might have to weld 2
thickness together due to the rolled lip on the tank
EDIT
For safety you SHOULD have 4" of the filler tube inside
the grommet(that was the spec we used for production so we
didnt end up with the problems that the Pinto had
EDIT
Sorry no pics... I did this stuff for Chrysler and we couldnt
take pics
Also try to get the filler tube angle and the inlet to the tank
within 1*-2* of each other
EDIT
this is the tank I have in my hot rod... I changed my mind
at the last minute not to use the stock filler.. mainly
because of the height that it would have went in at... being
a low or bottom fill you have to have a pretty good size air
vent going up near the top of the tiller and I didnt want the
second line