When I removed the fuel pump from the gas tank I found a round disk in the bottom of the tank. The disk is about 3 3/4" in diameter and about 1/4" thick. It has a bump in the middle that sticks up about 1" on one side and about 1" in diameter. On opposite ends of the disk and about 170 degrees apart from each other are two more smaller bumps. Since I can't post a picture, this is as close as I can show it! -____- If you look at the small bumps straight on from the side there is a square notch under each bump. This thing isn't shown in the Ford Thunderbird shop manual so I don't know if it needs to be somewhere in the tank or was it dropped into the tank during assembly. Anyone have any idea what it is? Thanks. I should also mention it is made from black plastic.