I had the same year and equipment on my '04 Expy. I was VERY uncomfortable going from a 4,400 lbs. trailer (23') to a 29' at 7,300 lbs. Back end was just too wiggly. Made for extremely unpleasant towing. I was just 50 pounds over on hitch weight.
If you already bought the trailer, you can try putting stiffer tires on the Expy along with a high quality weight distribution hitch with anti-sway, but I think you will still not be happy with the result.
Mike Butts
DW+DD+DS+Poodles
2017 Forest River Forester 3011DS (first MH!)
Previously 1999 Coleman Santa Fe pop-up, 2007 Kodiak 23SS hybrid, 2013 Sunset Trail 29SS travel trailer