I drove a 48 Chevrolet COE back in the 1950's and 1960's and there are a few things that I remember that might help.
Firstly, with a wheel lift or conventional body, what happens when you lift a towed vehicle is that you take weight off of the front axle. The effect is worse on a short wheelbase than it is on a longer wheelbase. Our COE was wonderful for maneuvereability, but I couldn't pick up as much as a conventional cab could. The problem didn't show up on cars and light trucks, but it did when larger trucks were towed. I remember one big GMC Dump Truck that I brought in from about 20 miles out where my front tires only touched the road about every three feet unless I touched the brakes.
The lighter weight on the front axle had a couple of other peculiarities also. On the good side, steering got easier when you were loaded.
On the bad side was the fact that the kingpins were installed with Torrington Thrust Bearings, not brass washers. When there was a little wear in the area and you hit a railroad truck, pot hole or good sized bump, you would get a shimmy that would threaten to take the steering wheel out of your hands. The only thing to do was to stop and then start up again. We tried Brass Thrust Washers, but it was too hard to steer, so we went back to the Torrington Bearings, drove a little more carefully and replaced them more often.
I didn't mention it, but we had a Holmes Traffic King double boomed wrecker on the truck and it had a 134" wheelbase. It was a model 5403.
I'm not trying to say not to do it, just telling you what to expect.
I had a barrelful of fun driving the wrecker and learned how to retrieve just about anything on wheels. It was a real intellectual challenge to figure out how to get a large truck back on its wheels and out of the ditch without collapsing a boom or breaking a cable and I managed to survive both of those calamities without killing myself.
