http://www.4x4wire.com/forums/showfl...40&Main=629550
depending how ya have the truck loaded I would say keeping it below 5000 lbs would be safe.
Increaseing your braking ability (different front brakes - dual calipers bigger disks - rear disks if you don;t have them - larder master cylinder to push more fluid to the increased capacity of dual piston calipers and rear disks)
Hydro boost also works great
helper springs or air bags in the rear to stop wheelies (hinders brakeing and steering)
taller gears
stronger rear axles
a trailer with brakes
trans cooler
oil cooler
all of these will help increase your ability to tow, however - if you are in an accident and you are over the manufactures rated weight, not sure a court of law will care what ya did, they will simply find you liable
just something to think about