As expected with a 1500, I have serious sag when towing my RV. Here's my setup:

In the bed, I have a kids quad and my dirtbike (about 380 lbs)
On the hitch, the RV (700 lb tongue weight with load-distributing hitch)

My truck is rated for 1625 lb load capacity, so its within limits, but the rear sags alot. Since Add-a-Leaf isn't an option, has anyone added air bag systems or stiffer springs? Interested in your thoughts on either, prices, etc.

 

Bag it. I have good, old fashioned leafs and I use air bags. I won't run Add-a-Leafs even though I can as they are just too damn stiff when not hauling or towing, but bags can be adjusted for load so they ride nice when not needed...

 

I started off with firestone airbags and they didn't survive my first winter. They got brittle and broke. I then tried the airlift brand bags and they are holding up a lot better this winter and they work wonders. Check around online and you should be able to get a set for under $100.

 

Just ordered the Air-Lift kit for $87 shipped. We shall see! Thanks for the help!

 

I'd either go with some Air Bags or a Timbren Kit, both will do the trick for you. www.sdtrucksprings.com has a lot of options for helper springs at a great price.

 

Any links to that air lift bags website? looks like a pretty reasonable price. Are they so called "plug and play" or is there additional parts needed. I will be towing in the near future and dont want to hassle with *** end sag when that time comes. THX

 

The airlift kit will come with everything you will need to install them. The most difficult part is getting them compressed and shoved into the coils but it is worth the hassle.

 

The price I quoted was just for the bags with hoses. There are all kinds of kits from just a T-fitting so they air up evenly to a full kit that has an onboard compressor to adjust each bag independently on the fly. The price goes up fast when adding options.

 

I would hook them up so you air them up independently, without the T fitting