72 Rear Gas Tank Replacement. Squeak Pads

[Ark Bigfoot]

I am replacing my rear gas tank on 72 Bronco with a 13 gal. I have put squeak pad all across the bottom holding strap. Should there be squeak pads other places like the top gas tank brackets (corners)? Did a test fit and discovered dirt dobbers home in the fill tube. Thinking about closing off the bottom end and filling with water and let set over night then pull a rag back and forth to remove. Any better way to destroy their home? Not for sure about the fill tube.