Re: installing a new permanant fuel tank
Assuming it is a metal tank, to the negative terminal of your battery. If it is a plastic tank, you don't need to.
Most people connect the negative terminal of the battery to a permanently mounted bus bar. Then anything else that needs grounding is attached to that bus bar.
In the case of the fuel tank, there should be a grounding attachment point on the tank. This is often a small tab sticking up on the top of the tank.
