I have a 1994 Ford F250 7.3 IDI 4x4 Super Cab. I also have a 1991 Newmar 5th Wheel with a GVWR of 11,000#. My gear ratio is 39, Spring 9F and GVWR is 8,800. Is this too much weight for my diesel to pull? Also trying the Pin Wight. Any help will be gr...