I'd suggest loading it as for travel (full water, gas, LP, food, etc, & passengers). Take it to a truck scale or other weighing place (I use an Allied Van Lines branch). Get it weighed. Compare to the GVW on the door or glove box sticker. The tire, wheel, and carrier are probably going to weigh in the neighborhood of 100#. Be sure you've got that margin.
Jim, "The doc said that my X-ray showed a broken rib, but not to worry. They'd fixed it with Photoshop."
'06 Tiger CX 'C Minus' on a Silverado 2500HD 4x4, 8.1 & Allison (aka 'Loafer's Glory')