I regularly pull 7000lbs of trailer behind my 2010 1500 with about 800lbs of tongue weight. I do not use a weight distribution hitch, but do have Timbren's installed to eliminate the sag.
Before I get jumped on about not using a WD hitch, and to qualify why I'm recommending you do use one, there are many factors to consider when it comes to towing big weight behind your truck. Without going into detail, you of course must ensure that you do not exceed any of the manufactures weight specs. It is also very important that you do not exceed the rating of the hitch components, and the hitch coupler (slug) is one that is often over looked. Most are rated at 500lbs, so be aware of that. I happen to use the 'Alumastinger' rated at 2000lbs tongue, so it is over rated compared to the actual hitch receiver.
The suspension in 1/2T trucks is not optimal for heavy towing, as a properly loaded trailer will place about 10% of it's gross weight on the hitch. If this weight exceeds 400lbs, suspension enhancement is desired and recommended to ensure the overall drivetrain geometry is maintained at a point to ensure best handling and minimize the off geometry loading a wear on drivetrain components.
As the length of the trailer increases, the load change on the hitch changes to a greater degree when driving through rises and dips, which leads to the reason I recommend you consider using a WD hitch. It will go a long way to control the hitch loading to ensure your truck stays well within geometric limits as well as ensure predictable handling.
Although under certain circumstances, you may be OK without suspension enhancement, I highly recommend it as yet another 'correct' thing to do to ensure overall safety and reliability. After all, when you consider the $ investment you have in the truck and trailer, the cost to enhance the suspension is very low.
The most popular suspension enhancements have already been mentions in the posts above, but I will summarize them -
1) Airlift 1000 - Inexpensive, relatively easy to install, adjustable (I have never used these myself)
2) Timbren SES - Slightly more expensive, ultra easy to install, not adjustable (I currently use these)
3) Total Load Control - More expensive, looks pretty straight forward to install, full adjustable (These are on my mod list for this summer)
So, why would I not consider the Airlift 1000, and replace my Timbrens with TLC ??
There are many success stories on this forum with the Airlift 1000, however I make my living with the equipment in the trailer, and a failed airbag (although not common, does happen) could cost me a lot more than then the cost of the whole trailer let alone the cost of a suspension enhancement system. The cold weather I usually have to deal with for many months of the year, and the experiences of others here with them is also a consideration for me.
The Timbrens are great....love them! However, there are times that I wish I had some control over the amount of enhancement, as I could then level my truck and adjust the rear suspension as required from time to time.
Total Load Control is offering a system that mounts where my Timbrens are, is made of a material proven to handle the weather I will require them to work in, and offers the adjustability I desire. The fact that TLC is a supporting site vendor is a real bonus.
If you ensure that your truck/trailer unit is setup for success, then you can enjoy your travels with piece of mind knowing that everything is designed to ensure safety and reliability. Which ever system/setup you choose, have a great time in your camping adventures, and take lots of pics to share with us. :smileup: