I bought a Holiday Rambler 38' Diesel Pusher in January.
It has a 330 CAT and pulls my 24 enclosed without a problem.
Towed to Richmond last month and ran 65 most of the way, lose a little on hills but not to much.
Just got back from Bowling Green, KY towing about 10K, down to 40 on 7% grades but I dought my dually would do much better, passed 18 wheelers on every hill! I don't know why I waited so long.