Removing filler neck on '70 Cuda gas tank?

[drag-n-cuda]

Is there a secret to doing this?  Does the tank seal have some kind of band clamp that I'm not seeing.  Trying to remove now. 

Quick, knowldgeable responses appreciated,
drag-n

[6packCuda]

The neck should just slide out of the tank when you lower the tank.

[drag-n-cuda]

I got it out, it was just tough.  Does anyone now why I found a 6" long by about .75" diameter compression spring inside the tank?  Not a clue where it came from and what it would be used for.  Maybe someone who didn't like me put it there.

Thanks,
drag-n

[DAYLEY/CHALLENGER]

If I remember correctly.........back in the day when they started switching to unleaded gas , there were springs that were available to be inserted into the filler tube  for some reason.  I thought the unleaded nozzles were smaller that the leaded ones but I could be wrong.  Anyway.........It had to do something about the correct nozzle size with the correct gasoline.  I know this sounds confusing and it is...........