As others have said, pin weight in the bed of the truck would be the main issue rather than the total weight of the trailer.
I have a 2004 Dodge Durango with the Hemi. We pulled or previous trailer for over 10 years. Fully loaded the trailer weighed about 5500 lbs. While the Durango was rated to 8500lbs there is no way I would think about pulling that much. The Hemi is a great engine and performed well with 5500lbs but that would be about my limit. We do live in a mountain state with many steep grades so that is a factor. If you live where its flat 6-7000lbs might be ok but no higher regardless of vehicle rating. You won't be happy!