Dan,
As has been said so many times on this and other forums - forget the tow ratings. With a 1/2 ton vehicle one usually runs out of payload for tongue/pin weight before hitting the maximum trailer towing capacity of the tow vehicle. Other concerns, as you go up in weight with a trailer, are the brakes going down grades and engine RPM and transmission temp going up those grades. (You mentioned the Smokey Mountains and National Parks.) If you search this forum, you'll find lots of threads on how to go about it, but many will advise loading your tow vehicle up (occupants, fuel, pets, hitch, junk, etc.) and head for the nearest CAT scales. Weight the axles separately. The difference between that scale weight - especially the rear axle - and the GVWR on the door sticker is what you have left for payload (tongue weight, in your case). Conventional trailers typically run about 12% of their loaded weight (go by GVWR on the trailer - NOT the dry weight) on the tongue. Keep in mind, also, that 4WD reduces your payload capacity because of the added weight of the transfer case and front drive axle. Search, research and read.
Rob
