I have the weights all listed in my thread about will a 1500 work or am I staying with a 2500.
I believe the class IV hitch is rated 1400 lbs with WDH. But, I do not believe the truck is.
Remember, your weight distribution hitch will also have a limit. Most are 1000 lb tongue and 10000lb trailer. Also, your ball must be atleast the same capacity.
For instance, I just bought a drop hitch for my HD. The hitch is rated 1300 lb tongue and 13000 lb trailer. I got a 2-5/16 hitch ball rated at 14000 lb. The hitch ball is really important to pay attention to as they range from 5000 to say 15000, but they all look just about the same.
If I get a chance I will get you more accurate numbers...or take a look through our towing section...they are in there.
And remember, 1000 lb tongue weight doesn't leave much for payload...so going bigger probably isn't a good idea.