An LD hitch is only part of the solution -- trying to 'jack up' the rear end by tightening the chains to the arms will just make the rear end-combo too rigid -- you'll lose the flexibility necessary to cope with ruts and sloping driveways, etc. (as an hilarious-to-picture, but exaggerated consequence, you could find yourself trying to converse a slight dip in the road and your rear wheels suspended in the air -- it will never really happen, but just think about this setup).

You really have to beef up the rear suspension -- go with overload springs and matching shocks; and don't forget to be sure that your tires (especially the rear) are load-rated, and inflated, for the extra load!