Gas tank swap questions.... again.

[Dale99]

I have searched on here quite a bit about swapping gas tanks to the 31gal from newer blazers/burbs. From that I know I have to remove/replace the rear cross member, and make a front or fab in the newer front. I have other questions that I did not see in the post I have read.

1. Do the tank flanges sit below the frame channels, or in the C of them?
2. Do I need to reposition the brake line bracket? Or bump the tank up to it?
3. The existing lines.. what do the ones going to the left rear go to? I know at least one going to the front is send, the other is a vent of some type? I have fill, and the fill/vent. But there are 3 going to something that is in the "bed"??
4. Was the original tank a self grounding tank as I only saw one wire going to it?