It is a good idea to contact them. I used to tow a Trail Sport 19RDB, which was similar to your unit in overall load rating. I chose to purchase a 10K rated unit which more than met my needs at that time. Once it was dialed in it worked very well - although I soon learned to keep the proper points lubricated.
I traded that RV in for a Puma that GV's out to 7600 so I am still well under the limit, yet am still safe. Some readjustment was necessary. I highly recommend perusing http://www.equalizerhitch.com/pdf/eq...anual_0111.pdf
the user manual, which really stresses the correct adjustments and what to watch for.
For me, despite the noise at low speed, the fact that even in wet conditions and severe cross-winds, the trailer and TV reacted as one, if they reacted at all. During flooding in upper NY state, I was forced to use 4x4 and maneuver across soaked, slippery mud slopes. The EQ kept the RV from becoming the heavy pendulum weight that would have dragged me to destruction.
And if it proves to be too much according to the factory? Bigger RV or sell that baby and buy the right model.