I don't know how far you're going, but I just got back from a trip to Puerto Penasco, Mx from Los Angeles, CA - about 500 miles. I tow my H16 with a Dodge Durango and had no problems with my cat or trailer. The only extra weight I had on the trailer was the weight of the rudder system and sail bag (full of sails, boom and hiking stick). We ran down the road for 80 mph for most of the trip. No problems. Just make sure the boat is securely strapped to the trailer. On trips, my boat becomes one with the trailer with ratchet ties.
Good luck-
John