Snotbubbles
Footballguy
Jim Brown averaged 6.4 YPC in 1963. This is well above what Dickerson, Barkley, OJ, or Peyton averaged. If you extrapolate it times the number of carries Dickerson had, Brown would have had about 2300 yards rushing.
Frankly I think Peterson's 2012 season is #2 on my list. He was a beast that year.
Except you can't extrapolate it out because past performance does not guarantee future results.
Jim Brown in the first 10 games of the 1963 season: 204 rushes (20.4 r/gm), 1447 yards, 7.1 ypc
Jim Brown in the last 4 games of the 1963 season: 87 carries (21.8 r/gm), 416 yards, 4.8 ypc
Brown never averaged over 6 ypc in his career outside of that season so I'd view his performance as an outlier that season which appeared to be regressing to the norm. Another 2 games based on the way his last month went may have only netted him an additional 200 yards or so.