Most states are going to require license and insurance on the 3100 if its wheels, even if its just two of them.
You don't mention what your are towing. In the State of Washington brakes are required on the towed load it the towed load weighs more than 40% of the towing vehicle. Your 3100 plus dolly will be about 3,500 pounds. To be legal here your tow vehicle will need to weigh about 8,750
A Diesel powered dually might be that heavy, but no 3/4-ton pickup or car will come even close unless you can borrow one of the president's new limousines..
If you have a truck that big rent a big trailer.
You need the heavy end of the truck at the front to assure you can steer the dolly. I once watched someone try to dolly a car with no motor. It was a joke and they never took it out of their own yard.
Taking apart a torque-tube drive shalt will not be a quick and dirty task but is necessary to protect the engine and transmission from turning the hole time.
I've towed substantial distances with both a trailer and a dolly. I was still young when I last pulled a dolly, my older hopefully more mature self sees both the danger and the challenges a dolly brings to the party.
I'd agree with the chorus above that answers use a trailer. Even surge brakes on the trailer are far better than a brake-less dolly.
You're operating in a state that have more rules and more draconian ways to enforce them than the state I do. Don't play games, do it right from the start.
