Gas tank sending unit ground strap replacement

I drilled a hole in the passenger side corner of the tank flange and ran a short ground strap to the frame rail. Due to the tank insulator between the floor and the tank , And the straps being coated the tank is not grounded. As soon as you tighten the sending unit up to the tank it is grounded to the tank by the large fastener. If you check continuity between the tank and the sending unit they are grounded together. The factory ground strap is not only grounding the sending unit but also the tank through the large fastener nut.