So after hours of breathing gas fumes, I'm finally wrapping up my 4th gen tank swap. I've test-mounted the filler neck and attempted to test for ground. The filler neck is painted so finding a spot on the filler neck to test for ground is a challenge. However, if I touch the unpainted flap on the inside of the neck it is a good ground. So technically, that little flap thing is attached to the rest of the filler neck so essentially the filler neck has to be grounded for that flapper to be grounded. Right? Are the fumes getting to me?

 

You don't need the filler grounded, but it you have it screwed to the body it will be fine