I say that I think your 7,000 is total weight (truck plus trailer) because I remember my 98 Dakota, V6, was rated for gross of 7500 lbs, or, after the weight of the truck was accounted for, 3500 lbs.

THAT truck, V6, 2wd, stick shift, club cab, weighed 4,000 empty!!

but I did put 1600 lbs of stone in the bed on more than one occasion, and drove about 9 miles with that weight. I basically told the guys to load it up until it was ALMOST bottomed out on the suspension. It drove perfectly fine, but it was also 35mph or less as I drove across town from the gravel yard to my house. absolutely NO highway at all.