Grounding stock gas tank ideas? No metal fuel line...

When I was finishing up my 73 Challenger, I realized that I'd purchased the short sending unit ground strap instead of the long one I needed. While the correct one was ordered, I drove the car to get an alignment and put some gas in the tank. The fuel gauge still worked without the ground strap.

On a freshly built car, the sending unit grounds through the tank/tank straps to the body. Now, when the car gets some age on it, that connection probably gets weaker and the ground strap takes over.