Very few Hemi 1500s with that low of tow rating. If the tow rating is accurate, then it's a 3.21 gear truck and heavily loaded with options.
That was also a crossover year, last year of the crappy 545rfe trans and first year 8HP. If you have the 8speed, even with the high gears, I wouldn't be concerned with a 6500-7klb trailer, although it will be right at the max of what I'd want to deal with.
If the 5speed trans, I wouldn't want to flog that thing as hard as a trailer that size will do out west.
Chassis wise, that trailer is fine, albeit, you'll need something for the weak coils in back. Rest of the truck is same chassi as the 9-10klb tow rating trucks.
Don't get all balled up over the "payload" and tongue weight. Rookie move that is exasterbated on this forum continuously. Focus more on what I said up top. The truck itself IS big enough and capable of handling the load safely. Its the performance aspect that is slightly concerning depending on there rest of the info that I filled in the blanks for you.
