Foam pad placement for the gas tank

[elkyman70]

Hi. I have an '81 that I pulled the fuel tank out of to fix a leak. When I pulled it out I noted 2 square foam pads on the floor of the car. I guessed that they maybe came from under the tank so when I went to put the tank back I realized that maybe they don't go under the tank. I looked in the manual and it doesn't address them nor could I find it anyplace else. Anyone know where they are supposed to go?