David, you're pretty much right on the weight capacity. When we took my cab off the rotisserie, it took 3 guys (couldn't use my engine hoist because of interference with my cab dolly (poor planning on my part there).
Here is a shot of my rotisserie that I built out of two engine stands. I went with brackets at the doors for access to the floor for repair.
I have been inside the cab while mounted on the rotisserie without issues and I'm a bit over 250.
