Here are the specs from the link you provided:
Year 2015
Manufacturer Forest River
Model Name Wildwood Midwest
Trim Name 31KQBTS
Generic Type (Primary)Travel Trailer
Dry Weight, Hitch 793 lbs.
Unloaded Weight 7,902 lbs.
GVWRTBD
Cargo Capacity 3,013 lbs.
Overall Length 36' 1"
Overall Height 11' 2"
Overall Width 96"
Fresh Water Capacity 40 gal.
Assuming you have kids since you have a burb and are buying a trailer with bunks. You'll easily add 1000 lbs of cargo to the trailer. It sounds like a lot, but consider clothes, food, pots/pans, etc etc etc and that 7900 lb trailer will likely weight about 9000 lbs packed and ready to go. Filling the fresh water tank will add another 350 lbs.
Likewise that 790 lb hitch weight will be more like 1100 lbs after you fill the propane tanks and load the trailer. The burb needs to carry that 100 lbs in addition to all the passengers and cargo, which will likely put you overweight. Changing the rear axle ratio will increase the towing capacity, but NOT the carrying capacity....that's a function of brakes, tires, and frame.
IMO that is WAAY too much trailer for a 1500 burb. For a comfortable tow with the family aboard you should be looking at trailers with a dry weight in the 5000 lb range. If DW has her heart set on that model, then look for a more HD tow vehicle like a 2500 burb, Excursion, 250/350 van or 250/350 pick-em-up truck.
If you want to try it, I'm sure the burb will pull it but it won't be a comfortable ride and you will more than likely toast the rear axle by the end of the season.
