Can`t remember where I found the data, but the heaviest recorded weight for a whitetail was indeed the one already mentioned here. 511 live weight, from minnesota.

The heaviest muley was 505 live weight, if I am remembering correctly.

I shot a whitetail that field dressed 294# in 2000, and the landowner of my lease in Illinois shot one in slug season that dressed at 328#.

400# live weight is not all that rare in midwest states.