Like iowajohn, I too towed with a 1500 dodge for many years ( many years too long ). i did gn and bumper pull. M's are pretty big. I don't have one but do have an H. I't's not an ideal feel.. I think you will run out odf suspension.. though the gn is better than bumper.
After years of white knucleing it.. i sold my 98 dodge and bought a 99 ford 350.
much better towing... safer.. etc..