I am probably wrong, but this chassis looks odd to me. Can't put my finger on it. It is a '51 COE 2 ton (158" wheelbase)and maybe just that it's a little "stubby" is doing it, but everytime I look at it, it doesn't seem right.
What do you think?

BTW, it had an optional factory frame extension on the rear. Later someone welded another piece of channel over it for more strength and recently it was cut off about an inch or so from the standard frame (probably so it would fit on the trailer for shipping).
http://s1276.photobucket.com/user/jsdesign2/library/51%20ceo