I went to a local cornfield where I have found some civil war relics yesterday. I was about 70 yards off the road and my ace 250 started jumping around. I have found lots of coal in the area so I eliminated that notch. But it was still going crazy. I put my shovel down and hit something hard. I need up digging a metal plate that is roughly 20" long, 7" wide and 1 1/4" thick but it weighs 55.4 lbs! I made it back to my car and got it home. I wiped it clean and there is no rust on it. There is a farm that still uses the field, but not sure if this came off a tractor? Here are the photos. The one is of the only marking I can find on the piece.